A student holds a bike wheel and starts it spinning with an initial angular speed of 9.0 rotations per second. The wheel is subject to some friction, so it gradually slows down. In the 10-s period following the inital spin, the bike wheel undergoes 65.0 complete rotations. Assuming the frictional torque remains constant, how much more time delta ts will it take the bike wheel to come to a complete stop? The bike wheel has a mass of 0.725 kg and a radius of 0.315 m. If all the mass of the wheel is assumed to be located on the rim, find the magnitude of the frictional torque τf that was acting on the spinning wheel.

Answers

Answer 1
Final answer:

After 10 seconds, the bike wheel will take roughly 15.98 seconds to come to a complete halt. The frictional torque operating on the spinning bike wheel is -0.112 N*m.

Explanation:

The process to solve this problem involves several steps. The first one is to determine the initial and final angular velocities of the wheel. Angular velocities are usually measured in radians per second, but we have them in rotations per second. So, firstly these values need to be converted by multiplying the number of rotations by 2π radians. The initial angular velocity, ωi, hence becomes

9 * 2π = 56.55 rad/s,

and after 10 seconds, the final angular velocity, ωf, is

65 / 10 * 2π = 40.84 rad/s.

Now, we already know 10 seconds.

Using these values, the angular acceleration (α) can be calculated as

(ωf - ωi) / Δt = (40.84 rad/s - 56.55 rad/s) / 10 s = -1.571 rad/s².

Note that this is negative because it's a deceleration. We're also given the wheel's mass (m) and radius (r), so the moment of inertia (I), which can be calculated as

I = m*r², will be 0.725 kg * (0.315 m)² = 0.071 kg*m².

From here, frictional torque (τf), which is the product of the moment of inertia and angular acceleration, can be found as

I * α = 0.071 kg*m² * -1.571 rad/s² = -0.112 N*m.

The negative sign just indicates the torque acts in the direction to slow down the wheel.

Finally, to find the time Δts it takes to come to rest, we can use the equation for angular velocity:

ω = ωi + α * t.

Setting ω to 0 (as the wheel stops) and solving for t gives us:

t = (0 - ωi) / α = - (40.84 rad/s) / -1.571 rad/s² = 25.98 s.

But our Δts is the time after the first 10 seconds, so Δts = t - 10 s = 15.98 s.

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Related Questions

8. A gas is contained in a horizontal piston-cylinder apparatus at a pressure of 350 kPa and a volume of 0.02 m3 . Determine the work done by the piston on the gas if the cylinder volume is increased to 0.15 m3 through heating. Assume the pressure of the

Answers

Answer:

45500 J

Explanation:

Pressure, P =350 kPa = 350 x 1000 Pa

V1 = 0.02 m^3

V2 = 0.15 m^3

Work done by the piston

W = Pressure x increase in volume

W = P x (V2 - V1)

W = 350 x 1000 (0.15 - 0.02)

W = 45500 J

Thus, the work done is 45500 J.

Final answer:

The piston performs 45500 Joules of work on the gas when the volume of the gas in the piston-cylinder apparatus increases from 0.02 m³ to 0.15 m³ at a constant pressure of 350 kPa.

Explanation:

To determine the work done by the piston on the gas when the cylinder volume increases from 0.02 m³ to 0.15 m³ at a constant pressure of 350 kPa, we can use the formula for work done during a quasi-static process in thermodynamics, which is W = PΔV, where W is the work done by the gas, P is the constant pressure, and ΔV is the change in volume.

Given:
P = 350 kPa = 350000 Pa (since 1 kPa = 1000 Pa)
ΔV = 0.15 m³ - 0.02 m³ = 0.13 m³

We can now calculate the work done:

W = PΔV
W = 350000 Pa × 0.13 m³
W = 45500 J

Therefore, the piston performs 45500 Joules of work on the gas when the volume increases to 0.15 m³.

A 3 kg steel ball falls down vertically and strikes a floor with a speed of 12 m/s. It bounces off upward with the same speed. If the ball is in contact with the floor for 0.12 s, what is the magnitude of the average force exerted on the ball by the floor?

Answers

Answer:

600N

Explanation:

If the ball bounces off upward with the same speed, the velocities before and after are equal and in opposite directions. That means the floor must have caused a momentum impact to change its direction.

By the law of momentum conservation:

[tex]mv + \Delta P_f = mV[/tex]

where m = 3 kg is the ball mass. v = -12 m/s is the velocity right before the impact. V = 12m/s is the velocity right after the impact. ΔP_f is the momentum caused by the floor.

[tex]\Delta P_f = m(V-v) = 3(12 - (-12)) = 3*24 = 72kgm/s[/tex]

Then the average force exerted during the 0.12s impact is

[tex]F = \frac{\Delta P_f}{\Delta t} = \frac{72}{0.12} = 600N[/tex]

Glycerin (C3H8O3) is a nonvolatile liquid. What is the vapor pressure of a solution made by adding 154 g of glycerin to 316 mL of H2O at 40.0°C? The vapor pressure of pure water at 40.0°C is 55.32 torr and its density is 0.992 g/cm3.

Answers

Answer:

[tex]P_{sol}=50.4\ mm.Hg[/tex]

Explanation:

According to given:

molecular mass of glycerin, [tex]M_g=3\times 12+8+3\times 16=92\ g.mol^{-1}[/tex]molecular mass of water, [tex]M_w=2+16=18\ g.mol^{-1}[/tex]∵Density of water is [tex]0.992\ g.cm^{-3}= 0.992\ g.mL^{-1}[/tex]∴mass of water in 316 mL, [tex]m_w=316\times 0.992=313.5 g[/tex]mass of glycerin, [tex]m_g=154\ g[/tex]pressure of mixture, [tex]P_x=55.32\ torr= 55.32\ mm.Hg[/tex]temperature of mixture, [tex]T_x=40^{\circ}C[/tex]

Upon the formation of solution the vapour pressure will be reduced since we have one component of solution as non-volatile.

moles of water in the given quantity:

[tex]n_w=\frac{m_w}{M_w}[/tex]

[tex]n_w=\frac{313.5}{18}[/tex]

[tex]n_w=17.42 moles[/tex]

moles of glycerin in the given quantity:

[tex]n_g=\frac{m_g}{M_g}[/tex]

[tex]n_g=\frac{154}{92}[/tex]

[tex]n_g=1.674 moles[/tex]

Now the mole fraction of water:

[tex]X_w=\frac{n_w}{n_w+n_g}[/tex]

[tex]X_w=\frac{17.42}{17.42+1.674}[/tex]

[tex]X_w=0.912[/tex]

Since glycerin is non-volatile in nature so the vapor pressure of the resulting solution will be due to water only.

[tex]\therefore P_{sol}=X_w\times P_x[/tex]

[tex]\therefore P_{sol}=0.912\times 55.32[/tex]

[tex]P_{sol}=50.4\ mm.Hg[/tex]

A rope is tied to a tree 4.5 feet from the ground and then run through a pulley hooked to a vehicle 33 feet from the tree. If a person stands at the tree and pulls ten feet of the rope (after all slack is taken up) how far will the vehicle move?

Answers

Final answer:

If a person pulls ten feet of the rope tied to a vehicle through a pulley, the vehicle will move the same distance, which is ten feet assuming ideal conditions with no slack or stretch in the system.

Explanation:

The question is asking about how far a vehicle moves when a rope attached to it and run through a pulley is pulled a certain distance. This scenario can be understood using the principles of distance and leverage as applied in physics. When you pull a rope through a pulley, the movement or distance covered by the object attached to the rope is equivalent to the length of the rope pulled.

In this case, if a person pulls ten feet of the rope, the vehicle will also move ten feet. It's important to note that this is applicable under ideal conditions where the rope and pulley do not stretch or bend and the there is no slack in the system.

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A mass of 0.56 kg is attached to a spring and set into oscillation on a horizontal frictionless surface. The simple harmonic motion of the mass is described by x(t) = (0.42 m)cos[(6 rad/s)t]. Determine the following. (a) amplitude of oscillation for the oscillating mass m (b) force constant for the spring N/m (c) position of the mass after it has been oscillating for one half a period m (d) position of the mass one-third of a period after it has been released m (e) time it takes the mass to get to the position x = −0.10 m after it has been released

Answers

Answer:

(a) 0.42 m

(b) 20.16 N/m

(c) - 0.42 m

(d) - 0.21 m

(e) 17.3 s

Solution:

As per the question:

Mass, m = 0.56 kg

x(t) = (0.42 m)cos[cos(6 rad/s)t]

Now,

The general eqn is:

[tex]x(t) = Acos\omega t[/tex]

where

A = Amplitude

[tex]\omega[/tex] = angular frequency

t = time

Now, on comparing the given eqn with the general eqn:

(a) The amplitude of oscillation:

A = 0.42 m

(b) Spring constant k is given by:

[tex]\omega = \sqrt{k}{m}[/tex]

[tex]\omega^{2} = \frac{k}{m}[/tex]

Thus

[tex]k = m\omega^{2} = 0.56\times 6^{2} = 20.16\ N/m[/tex]

(c) Position after one half period:

[tex]x(t) = 0.42cos\pi = - 0.42\ m[/tex]

(d) After one third of the period:

[tex]x(t) = 0.42cos(\frac{2\pi}{3}) = - 0.21\ m[/tex]

(e) Time taken to get at x = - 0.10 m:

[tex]-0.10 = 0.42cos6t[/tex]

[tex]6t = co^{- 1} \frac{- 0.10}{0.42}[/tex]

t = 17.3 s

Final answer:

The amplitude of oscillation is 0.42 m. The force constant of the spring is approximately 0.03 N/m. The position of the mass after one half a period, one-third of a period, and at x = -0.10 m can be determined using the given equation x(t).

Explanation:

The amplitude of oscillation is the maximum displacement from the equilibrium position. In this case, the amplitude is given as 0.42 m.

The force constant (k) of the spring can be determined using Hooke's Law, which states that the force exerted by a spring is proportional to the displacement from equilibrium. In this case, the force constant is calculated by dividing the mass (0.56 kg) by the square of the angular frequency (6 rad/s) squared, which gives a force constant of approximately 0.03 N/m.

The position of the mass after it has been oscillating for one half a period can be found by substituting the value of time (T/2) into the equation x(t), which gives a position of approximately -0.42 m.

The position of the mass one-third of a period after it has been released can be determined by substituting the value of time (T/3) into the equation x(t), which gives a position of approximately 0.33 m.

The time it takes the mass to get to the position x = -0.10 m after it has been released can be found by rearranging the equation x(t) and solving for time. The time is approximately 0.14 seconds.

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At a certain location, Earth's magnetic field of 34 µT is horizontal and directed due north. Suppose the net field is zero exactly 8.1 cm above a long, straight, horizontal wire that carries a constant current. What are (a) the magnitude of the current and (b) the angle between the current direction and due north?

Answers

Answer:

a) I = 13.77 A

b) 0 ° or to the East

Explanation:

Part a

The magnetic field by properties would be 0 at the radius on this case r =8.1 cm.Analyzing the situation the wirde would produce a magnetic field equals in magnitude to the magnetic field on Earth by with the inverse direction.

The formula for the magnetic field due to a wire with current is:

[tex] B = \frac{\mu_0 I}{2 \pi r} [/tex]

In order to have a value of 0 for the magnetic field at the radius then we need to have this balance

B (r=8.1) = B (Earth)

Replacing:

[tex] B = \frac{\mu_0 I}{2 \pi r)}= B_{Earth} [/tex]

Solving from I, from the last equation we got:

[tex] I = \frac{2 \pi r B_{earth}}{\mu_0} [/tex]

[tex] I=\frac{2 \pi 0.081 m (34 x 10^{-6} T)}{4 \pi x 10^{-7} Tm/A}[/tex] = 13.77 A

Part b

We can use the right hand rule for this case.

The magnetic field of the wire would point to the South, because the magnetic field of the earth given points to the North. Based on this the current need's to flow from West to East in order to create a magnetic field pointing to the south, because the current would be perpendicular to the magnetic field created.

Three masses (3 kg, 5 kg, and 7 kg) are located in the xy-plane at the origin, (2.3 m, 0), and (0, 1.5 m), respectively.
A) Determine the center of mass of the system.
B) A 6 kg mass is added to the system. This four-mass system has a new center of mass at the origin. What is the location of the 6 kg mass?

Answers

Answer:

a) C.M [tex]=(\bar x, \bar y)=(0.767,0.7)m[/tex]

b) [tex](x_4,y_4)=(-1.917,-1.75)m[/tex]

Explanation:

The center of mass "represent the unique point in an object or system which can be used to describe the system's response to external forces and torques"

The center of mass on a two dimensional plane is defined with the following formulas:

[tex]\bar x =\frac{\sum_{i=1}^N m_i x_i}{M}[/tex]

[tex]\bar y =\frac{\sum_{i=1}^N m_i y_i}{M}[/tex]

Where M represent the sum of all the masses on the system.

And the center of mass C.M [tex]=(\bar x, \bar y)[/tex]

Part a

[tex]m_1= 3 kg, m_2=5kg,m_3=7kg[/tex] represent the masses.

[tex](x_1,y_1)=(0,0),(x_2,y_2)=(2.3,0),(x_3,y_3)=(0,1.5)[/tex] represent the coordinates for the masses with the units on meters.

So we have everything in order to find the center of mass, if we begin with the x coordinate we have:

[tex]\bar x =\frac{(3kg*0m)+(5kg*2.3m)+(7kg*0m)}{3kg+5kg+7kg}=0.767m[/tex]

[tex]\bar y =\frac{(3kg*0m)+(5kg*0m)+(7kg*1.5m)}{3kg+5kg+7kg}=0.7m[/tex]

C.M [tex]=(\bar x, \bar y)=(0.767,0.7)m[/tex]

Part b

For this case we have an additional mass [tex]m_4=6kg[/tex] and we know that the resulting new center of mass it at the origin C.M [tex]=(\bar x, \bar y)=(0,0)m[/tex] and we want to find the location for this new particle. Let the coordinates for this new particle given by (a,b)

[tex]\bar x =\frac{(3kg*0m)+(5kg*2.3m)+(7kg*0m)+(6kg*a)}{3kg+5kg+7kg+6kg}=0m[/tex]

If we solve for a we got:

[tex](3kg*0m)+(5kg*2.3m)+(7kg*0m)+(6kg*a)=0[/tex]

[tex]a=-\frac{(5kg*2.3m)}{6kg}=-1.917m[/tex]

[tex]\bar y =\frac{(3kg*0m)+(5kg*0m)+(7kg*1.5m)+(6kg*b)}{3kg+5kg+7kg+6kg}=0m[/tex]

[tex](3kg*0m)+(5kg*0m)+(7kg*1.5m)+(6kg*b)=0[/tex]

And solving for b we got:

[tex]b=-\frac{(7kg*1.5m)}{6kg}=-1.75m[/tex]

So the coordinates for this new particle are:

[tex](x_4,y_4)=(-1.917,-1.75)m[/tex]

A rectangular coil of dimensions 5.40cm x 8.50cm consists of25 turns of wire. The coil carries a current of 15.0 mA.
a) Calculate the magnitude of its magnetic moment
b) Suppose a uniform magnetic field of magnitude of 0.350 T isapplied parallel to the plane of the loop. What is the magnitude ofthe torque acting on the loop?

Answers

Answer:

(a) Magnetic moment will be [tex]17.212\times 10^{-4}A-m^2[/tex]

(b) Torque will be [tex]6.024\times 10^{-4}N-m[/tex]

Explanation:

We have given dimension of the rectangular 5.4 cm × 8.5 cm

So area of the rectangular coil [tex]A=5.4\times 8.5=45.9cm^2=45.9\times 10^{-4}m^2[/tex]

Current is given as [tex]i=15mA=15\times 10^{-3}A[/tex]

Number of turns N = 25

(A) We know that magnetic moment is given by [tex]magnetic\ moment=NiA=25\times 45.9\times 10^{-4}\times 15\times 10^{-3}=17.212\times 10^{-4}A-m^2[/tex]

(b) Magnetic field is given as B = 0.350 T

We know that torque is given by [tex]\tau =BINA=0.350\times 15\times 10^{-3}\times 25\times 45.9\times 10^{-4}=6.024\times 10^{-4}N-m[/tex]

Final answer:

a) The magnitude of the magnetic moment is 0.0172 A·m². b) The magnitude of the torque on the loop is 0 N·m.

Explanation:

a) To calculate the magnitude of the magnetic moment, we can use the formula μ = nIA, where μ is the magnetic moment, n is the number of turns, I is the current, and A is the area of the coil. In this case, n = 25, I = 15.0 mA = 0.015 A, and A = (5.40 cm)(8.50 cm) = 45.9 cm² = 0.00459 m². Plugging these values into the formula, we get μ = (25)(0.015 A)(0.00459 m²) = 0.0172 A·m².

b) To calculate the magnitude of the torque, we can use the formula τ = μBsinθ, where τ is the torque, μ is the magnetic moment, B is the magnetic field strength, and θ is the angle between μ and B. In this case, μ = 0.0172 A·m² (calculated in part a),

B = 0.350 T, and since the magnetic field is applied parallel to the plane of the loop, θ = 0°.

Plugging these values into the formula, we get τ = (0.0172 A·m²)(0.350 T)(sin 0°)

= 0 N·m.

Light is incident along the normal to face AB of a glass prism of refractive index 1.54. Find αmax, the largest value the angle α can have without any light being refracted out of the prism at face AC if the prism is immersed in water (with index of refraction 1.33). Express your answer in degrees. Ignore any reflections from the surface BC.

Answers

To solve this problem it is necessary to use the concepts related to Snell's law.

Snell's law establishes that reflection is subject to

[tex]n_1sin\theta_1 = n_2sin\theta_2[/tex]

Where,

[tex]\theta =[/tex] Angle between the normal surface at the point of contact

n = Indices of refraction for corresponding media

The total internal reflection would then be given by

[tex]n_1 sin\theta_1 = n_2sin\theta_2[/tex]

[tex](1.54) sin\theta_1 = (1.33)sin(90)[/tex]

[tex]sin\theta_1 = \frac{1.33}{1.54}[/tex]

[tex]\theta = sin^{-1}(\frac{1.33}{1.54})[/tex]

[tex]\theta = 59.72\°[/tex]

Therefore the [tex]\alpha_{max}[/tex] would be equal to

[tex]\alpha = 90\°-\theta[/tex]

[tex]\alpha = 90-59.72[/tex]

[tex]\alpha = 30.27\°[/tex]

Therefore the largest value of the angle α is 30.27°

The largest value the angle α can have without any light being refracted out of the prism at face AC is 30.27°.

How to calculate the angle?

From the information given, the total internal reflection would be:

1.54sinb = (1.33) sin90°

sin b = (1.33 sin90° / 1.54)

b = 59.72°

Therefore, the value of the angle will be:

= 90° - 59.72°

= 30.27°

In conclusion, the correct option is 30.27°.

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Hoover Dam on the Colorado River is the highest dam in the United States at 221m, with a power output of 680 MW. The dam generates electricity by flowing water down to a point 150 m below the stop, at an average flow rate of 650 m3/s.
Part (a) Calculate the power in this flow in watts.

Answers

Answer:

Power = 9.75 ×10^8[tex]\frac{kgm^2}{s^3}[/tex]

Explanation:

Power is rate of change of energy.Here gravitational energy is transferred to kinetic energy of water at a definite rate.

For one second 650m^3 of water flows out down to 150m oh depth.

So, the energy at a height of 150m is transformed to kinetic energy.

for a second,

       650m^3 of water flows down ⇒ (1000kg/m^3 × 650m^3) = 6.5×10^5kg of warer flos down.

The total gravitational potential energy stored in water is

    = mass of water × height× gravity

    = 6.5 ×10^5 × 150 × 10 =  9.75 ×10^8[tex]\frac{kgm^2}{s^2}[/tex]

As it is transformed in a second it is also equal to Power.

Answer:

power = 1407.77 MW

Explanation:

The basic principle of a hydro electric station is the conversion of potential energy to electrical energy. Here, water is allowed to fall from a height which will increase its the kinetic energy. This high speed flowing water is used to rotate the shaft of a turbine which will in turn produce electrical energy.

So here,

power = rate of change of potential energy with respect to time

power = [tex]\frac{d(mgh)}{dt}[/tex]

where,

m = mass of water

g = acceleration due to gravity

h = height through which the water falls

here h and g are constants ( h is the total height through which the water falls and it doesn't change with time). Therefore we can take them out of differentiation.

thus,

power = gh[tex]\frac{d(m)}{dt}[/tex]

now,

m = ρV

where,

ρ = density

V = volume

substituting this in the above equation we get,

power = gh[tex]\frac{d(ρV)}{dt}[/tex]

again ρ is a constant. Thus,

power = ρgh[tex]\frac{d(V)}{dt}[/tex]

Given that,

h = 221 m

[tex]\frac{d(V)}{dt}[/tex] = 650 [tex]m^{3}[/tex]/s

g = 9.8 m/[tex]s^{2}[/tex]

ρ = 1000 kg/[tex]m^{3}[/tex]

substituting these values in the above equation

power =  1000 x 9.8 x 221 x 650

power = 1407.77 MW

A 50-N crate is pulled up a 5-m inclined plane by a worker at constant velocity. If the plane is inclined at an angle of 37° to the horizontal and there exists a constant frictional force of 10 N between the crate and the surface, what is the force applied by the worker?

Answers

Answer:F=40.09 N

Explanation:

Given

weight of crate [tex]W=50 N[/tex]

Inclination [tex]\theta =37^{\circ}[/tex]

Frictional Force [tex]f=10 N[/tex]

as the crate is moving with constant velocity therefore net Force on crate is zero

[tex]F-50\sin (37)-f=0[/tex]

[tex]F=50\sin (37)+10[/tex]

[tex]F=30.09+10[/tex]

[tex]F=40.09 N[/tex]

006 10.0 points Two pucks of equal mass collide. One puck (puck A) is stationary before the collision. After the collision the puck that was initially stationary moves along in the same direction in which the puck that hit it (puck B) was initially moving. Puck B Puck A Which of the following statements is correct if the total energy of the system is conserved during the collision (elastic collision)? 1. There isn't enough information to answer the question. 2. Both pucks slide past the point of colli- sion. 3. The puck B remains at the point of colli- sion. 4. The puck B rebounds.

Answers

Answer: 3. The puck B remains at the point of collision.

Explanation:

Assuming no external forces acting during the collision, total momentum must be conserved.

The initial momentum is due only to puck B, as Puck A is at rest.

The final momentum is given by the sum of the momenta of both pucks, so we can write the following equation:

mA*viA = (mA * vfA) + (mB * vfB)

As mA = mB = m, we can simplify the former equation as follows:

viA = vfA + vfB   (1)

Now, we also know, that the collision was an elastic collision, so total kinetic energy must be conserved too:

½ m viA²= ½ m vfA² + ½ m vfB²

Simplifying on both sides, we finally have:

viA² = vfA² + vfB²   (2)

Now, if we square both sides of (1), we get:

viA² = (vfA + vfB)²= vfA² + 2* vfA * vfB  +vfB² (3)

As the right side in (2) and (3) must be equal each other (as the left sides do), the only choice is that either vfA or vfB, be zero.

As we are told that puck A (initially stationary) after the collision, moves, the only possible choice is that puck B remain at rest in the point of collision, after the collision, exchanging his speed with puck A.

Final answer:

In an elastic collision where the total energy of the system is conserved, Puck B rebounds. This is because kinetic energy, along with momentum, is conserved in such a collision, causing the moving puck to rebound.

Explanation:

Considering this scenario from the lens of physics, the principle of conservation of momentum and kinetic energy comes into play, which means the total momentum and kinetic energy before and after the collision should remain constant. This is consistent with the properties of an elastic collision. Both pucks have the same mass and initially, Puck B is in motion while Puck A is stationary. Hence, all of the initial energy and momentum are with Puck B.

Upon collision, the energy is transferred, causing Puck A to move in the same direction that Puck B was initially moving. The correct statement is that if the collision is elastic and the total energy of the system is conserved, 'Puck B rebounds'. This rebounding comes from the conservation of kinetic energy principle which holds in an elastic collision. That is, the total initial kinetic energy equals the total final kinetic energy.

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The colors of the stars in the sky range from red to blue. Assuming that the color indicates the frequency at which the star radiates the maximum amount of electromagnetic energy, estimate the surface temperature of red, yellow, white, and blue stars.
A) Estimate the surface temperature of red star. Assume that red color corresponds to wavelengths of approximately 650 nm.B) Estimate the surface temperature of yellow star. Assume that yellow color corresponds to wavelengths of approximately 570 nm.C) Estimate the surface temperature of blue star. Assume that blue color corresponds to wavelengths of approximately 470 nmD) Estimate the surface temperature of white star. Since green is in the middle of the visible spectrum, choose 520 nm wavelength for white star.

Answers

Answer:

a) 4458K b) 5048K, c) 6166K, d) 5573K

Explanation:

The temperature of the stars and many very hot objects can be estimated using the Wien displacement law

    [tex]\lambda_{max}[/tex] T = 2,898 10⁻³ [m K]

    T = 2,898 10⁻³ / [tex]\lambda_{max}[/tex]

a) indicate that the wavelength is

    Lam = 650 nm (1 m / 109 nm) = 650 10⁻⁹ m

    Lam = 6.50 10⁻⁷ m

    T = 2,898 10⁻³ / 6.50 10⁻⁷

    T = 4,458 10³ K

    T = 4458K

b) lam = 570 nm = 5.70 10⁻⁷ m

    T = 2,898 10⁻³ / 5.70 10⁻⁷

    T = 5084K

c) lam = 470 nm = 4.70 10⁻⁷ m

    T = 2,898 10⁻³ / 4.7 10⁻⁷

    T = 6166K

d) lam = 520 nm = 5.20 10⁻⁷ m

    T = 2,898 10⁻³ / 5.20 10⁻⁷

    T = 5573K

A ) the surface temperature of red star is about 4500 K

B ) the surface temperature of yellow star is about 5100 K

C ) the surface temperature of blue star is about 6200 K

D ) the surface temperature of white star is about 5600 K

[tex]\texttt{ }[/tex]

Further explanation

Let's recall the Wien's Displacement Law as follows:

[tex]\boxed {\lambda_{max}\ T = 2.898 \times 10^{-3} \texttt{ m.K}}[/tex]

where:

λ_max = the wavelength of the maximum radiation energy ( m )

T = surface temperature of the star ( K )

Let us now tackle the problem!

[tex]\texttt{ }[/tex]

Given:

wavelength of red light = λ_r = 650 nm = 650 × 10⁻⁹ m

wavelength of yellow light =  λ_y = 570 nm = 570 × 10⁻⁹ m

wavelength of blue light =  λ_b = 470 nm = 470 × 10⁻⁹ m

wavelength of white light =  λ_w = 520 nm = 520 × 10⁻⁹ m

Asked:

A ) the surface temperature of red star = T_r = ?

B ) the surface temperature of yellow star = T_y = ?

C ) the surface temperature of blue star = T_b = ?

D ) the surface temperature of white star = T_w = ?

Solution:

Part A) :

[tex]T_r = ( 2.898 \times 10^{-3} ) \div \lambda_r[/tex]

[tex]T_r = ( 2.898 \times 10^{-3} ) \div ( 650 \times 10^{-9} )[/tex]

[tex]\boxed {T_r \approx 4500 \texttt{ K} }[/tex]

[tex]\texttt{ }[/tex]

Part B) :

[tex]T_y = ( 2.898 \times 10^{-3} ) \div \lambda_y[/tex]

[tex]T_y = ( 2.898 \times 10^{-3} ) \div ( 570 \times 10^{-9} )[/tex]

[tex]\boxed {T_y \approx 5100 \texttt{ K} }[/tex]

[tex]\texttt{ }[/tex]

Part C) :

[tex]T_b = ( 2.898 \times 10^{-3} ) \div \lambda_b[/tex]

[tex]T_b = ( 2.898 \times 10^{-3} ) \div ( 470 \times 10^{-9} )[/tex]

[tex]\boxed {T_b \approx 6200 \texttt{ K} }[/tex]

[tex]\texttt{ }[/tex]

Part D) :

[tex]T_w = ( 2.898 \times 10^{-3} ) \div \lambda_w[/tex]

[tex]T_w = ( 2.898 \times 10^{-3} ) \div ( 520 \times 10^{-9} )[/tex]

[tex]\boxed {T_w \approx 5600 \texttt{ K} }[/tex]

[tex]\texttt{ }[/tex]

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[tex]\texttt{ }[/tex]

Answer details

Grade: High School

Subject: Mathematics

Chapter: Energy

What impulse occurs when an average force of 7.0 N is exerted on a cart for 2.5 s ?

Express your answer to two significant figures and include the appropriate units.

Answers

Answer:[tex]1.7\times 10[/tex]

Explanation:

Given

Force [tex]F=7 N[/tex]

time interval [tex]t=2.5 s[/tex]

Impulse is given by [tex]=Force \times time\ interval\ for\ applied\ force [/tex]

[tex]Impulse=7\times 2.5=17.5[/tex]

For two significant Figure

[tex]Impulse=1.7\times 10[/tex]

                       

n this example we will look at the periodic motion of an ultrasonic transducer, a kind of ultrasonic loudspeaker used for medical diagnosis. The transducer is oscillating at a frequency of 6.7 MHz (6.7×106Hz). How much time does each oscillation take, and what is the angular frequency?

Answers

Answer:

Explanation:

frequency, f = 6.7 MHz = 6.7 x 10^6 Hz

Time period is defined as the time taken by the oscillating body to complete one oscillation.

the formula for the time period is

T = 1/ f = 1 / (6.7 x 10^6) = 1.5 x 10^-7 second

The angular frequency is given  by

ω = 2 π f = 2 x 3.14 x 6.7 x 10^6

ω = 4.2 x 10^7 rad/s

Final answer:

The time for each oscillation is approximately 1.49 x 10^-7 seconds, and the angular frequency is approximately 4.21 x 10^7 rad/s.

Explanation:

To find the time for each oscillation, we can use the formula T = 1/f, where T represents the period and f represents the frequency. In this case, the frequency is given as 6.7 MHz, which is equivalent to 6.7 x 10^6 Hz. So, substituting the value of the frequency into the formula, we get: T = 1 / (6.7 x 10^6) = 1.49 x 10^-7 seconds. Therefore, each oscillation takes approximately 1.49 x 10^-7 seconds.

The angular frequency can be calculated using the formula ω = 2πf, where ω represents the angular frequency and f represents the frequency. Substituting the given value of the frequency into the formula, we get: ω = 2π x 6.7 x 10^6 = 4.21 x 10^7 rad/s. Therefore, the angular frequency is approximately 4.21 x 10^7 rad/s.

A conducting sphere of radius r1= 0.38m has a total charge of Q=.75 uC. A second uncharged conducting sphere of radius r2= 0.28m is then connected to the first by a thin conducting wire. The spheres are separated by a very large distance to their size. What is the total charge on sphere two, Q2, in C?

Answers

Answer:

The Q₂ is 0.318 μC

Explanation:

The charge flows is the same on both, then:

[tex]V_{1} =\frac{kQ_{1} }{r_{1} } \\V_{2} =\frac{kQ_{2} }{r_{2} } \\Q_{2} =Q-Q_{1} \\\frac{kQ_{1} }{r_{1} } =\frac{k*(Q-Q_{1}) }{r_{2} } \\Q_{1} =\frac{\frac{Q}{r_{2} } }{(1/r_{1})+(1/r_{2}) }[/tex]

But:

[tex]\frac{1}{r_{1} } +\frac{1}{r_{2} }=\frac{1}{0.38} +\frac{1}{0.28} =6.2[/tex]

Q = = 0.75 μC

Replacing:

[tex]Q_{1} =\frac{\frac{0.75}{0.28} }{6.2} =0.432\mu C[/tex]

The Q₂ is equal:

Q₂ = 0.75 - 0.432 = 0.318 μC

Final answer:

The second conducting sphere, once connected and then disconnected from the first, ends up with the same charge as the first sphere, 0.75 µC or 0.75 x 10^-6 C.

Explanation:

When two conducting spheres are connected by a thin conducting wire, the charge distributes itself evenly across both spheres, assuming both spheres are identical in size. In the case of spheres with different radii, the amount of charge on each sphere once they are separated again will still be proportional to the original amount. Since the two spheres in the question are described to be separated by a large distance relative to their size, the thin wire connecting them would create an equipotential surface, allowing the charge to redistribute.

The total charge Q is conserved in the system, thus the charge on the second sphere Q2 after disconnecting the wire would be the same as the initial total charge Q since it was not charged before. Therefore, the total charge on sphere two, Q2, will also be 0.75 μC or 0.75 x 10^{-6} C.

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The auditory canal behaves like a resonant tube to aid in hearing. One end terminated at the eardrum, while the other opens to the outside. Typically, the canal is about 2.4 cm long. At which frequency would it resonate in its first harmonic?
4.2 kHz
3.6 kHz
2.9 kHz
5.7 kHz

Answers

Answer:

3.6 kHz

Explanation:

The pipes behave like a closed pipe . The end open is the end of the air canal outside the ear and the closed end is the eardrum.

The first harmonic will be as seen in the figure attached.

The length of the first harmonic will be λ/4.

λ/4=2.4 cm

λ=2.4 * 4=9.6 cm 0.096 m

Speed of Sound- 344 m/s(in air)

velocity(v) * Time Period(T) = Wavelength (λ)

Also, Time Period(T)= \frac{\textrm{1}}{\textrm{Frequency(f)}}

\frac{\textrm{Velocity}}{\textrm{Wavelength}}=\frac{\textrm{1}}{\textrm{Time Period}} =Frequency

Plugging in the values into the equation,

Frequency = [tex]\frac{344}{0.096}[/tex] Hz

                  = 3583.3 Hz≈3600 Hz= 3.6 kHz

Frequency= 3.6 kHz

Answer:

3.6 kHz

Explanation:

The auditory canal is a closed pipe because it has one closed end, the end terminated at the eardrum.

The length of the first harmonic of a closed pipe is given as;

L = λ/4 --------------------  (i)

where L = Length

and λ = wavelength

2.4 = λ/4

λ = 2.4 x 4 = 9.6 cm

Also, v = fλ  ------------------ (ii)

where v = speed of sound in air = 344 m/s

f = frequency of wave in Hertz

f = v/λ ------------------ (iii)

convert 9.6 cm to m = 0.096 m

substitute for λ and v in (iii)

[tex]f = \frac{344}{0.096} = 3583.33[/tex]

3583.33 Hz = 3600 Hz = 3.6 kHz

A 5 kg ball takes 13.3 seconds for one revolution around the circle. What's the magnitude of the angular velocity of this motion?

Answers

Answer: 0.47 rad/sec

Explanation:

By definition, the angular velocity is the rate of change of the angle traveled with time, so we can state the following:

ω = ∆θ/ ∆t

Now, we are told that in 13.3 sec, the ball completes one revolution around the circle, which means that, by definition of angle, it has rotated 2 π rad (an arc of 2πr over the radius r), so we can find ω as follows:

ω = 2 π / 13.3 rad/sec = 0.47 rad/sec

Answer:

0.472rad/s

Explanation:

Angular velocity = 2πf where f = frequency and frequency is the number of revolution per second and 2π represent a cycle of revolution. The mass of the body was 5kg, the time taken to complete a cycle was 13.3 s.

Frequency = 1/period where period is the time it takes to complete a revolution.

F = 1/13.3 = 0.075hz

Angular velocity = 2* 3.142* 0.075 = 0.472rad/s

Moe is carrying and supporting a large crate by exerting 1000 N. He is walking at constant velocity across a level, horizontal floor. If he covers a distance of 10 meters, how much work does he do on the crate? Use g = 10m/s2 if needed. Ignore friction between Moe and the crate.

Answers

Answer:

he did not work on the create

Explanation:

Honestly I have no idea it makes a lot of sense to use the work equation so that was my first answer but for some reason on UT Quest it said that was the wrong and moe not doing any work on the create was the right answer

Final answer:

The work done by Moe on the crate is 10,000 J.

Explanation:

The work done by Moe on the crate can be calculated using the formula:

Work = Force x Distance x Cosine(theta)

Since Moe is exerting a force of 1000 N and the distance covered is 10 meters, we can plug these values into the formula:

Work = 1000 N x 10 m x Cosine(0°)

The angle theta is 0° because Moe is exerting a force in the same direction as the displacement.

Cosine(0°) is equal to 1, so the work done by Moe on the crate is:

Work = 1000 N x 10 m x 1 = 10,000 J

Two masses sit at the top of two frictionless inclined planes that have different angles. Which mass gets to the bottom first?

Answers

Answer:

Explanation:

Let the two inclined planes having angle of inclinations α and β.

The acceleration along the inclined plane acting on the body is gSinα and gSinβ.

If α > β

So, g Sinα > g Sinβ

So, more the inclination of the plane more be the acceleration of body and hence the time taken is less.

So, the body kept on the inclined whose inclination is more reaches at the bottom first.

The mass sitting on the plane inclined to a greater angle to the horizontal will reach the bottom first because it will experience greater acceleration.

Let the angle of inclination of the first mass to the horizontal = θLet the angle of inclination of the second mass to the horizontal = β

The net horizontal force on the masses is calculated as follows;

[tex]\Sigma F_x = 0\\\\mgsin(\theta) = ma\\\\gsin(\theta) = a\ \ \ or \ \ \ \\\\gsin(\beta ) = a[/tex]

Assuming the value of the angles of inclination of the plane is the following;

θ = 60⁰   and  β = 30⁰

a = gsin(60) = 0.866g

a = gsin(30) = 0.5g

Thus, we can conclude that the mass sitting on the plane inclined to a greater angle to the horizontal will reach the bottom first because it will experience greater acceleration.

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A 200-Ω resistor is connected in series with a 10-µF capacitor and a 60-Hz, 120-V (rms) line voltage. If electrical energy costs 5.0¢ per kWh, how much does it cost to leave this circuit connected for 24 hours?

Answers

Answer:

Cost to leave this circuit connected for 24 hours is $ 3.12.

Explanation:

We know that,

[tex]\mathrm{X}_{\mathrm{c}}=\frac{1}{2 \pi \mathrm{fc}}[/tex]

f = frequency (60 Hz)

c= capacitor (10 µF = [tex]10^-6[/tex])  

[tex]\mathrm{X}_{\mathrm{c}}=\text { Capacitive reactance }[/tex]

Substitute the given values

[tex]\mathrm{X}_{\mathrm{c}}=\frac{1}{2 \times 3.14 \times 10 \times 10^{-6} \times 60}[/tex]

[tex]\mathrm{X}_{\mathrm{c}}=\frac{1}{3.768 \times 10^{-3}}[/tex]

[tex]\mathrm{x}_{\mathrm{c}}=265.39 \Omega[/tex]

Given that, R = 200 Ω

[tex]X^{2}=R^{2}+X c^{2}[/tex]

[tex]X^{2}=200^{2}+265.39^{2}[/tex]

[tex]X^{2}=40000+70431.85[/tex]

[tex]X^{2}=110431.825[/tex]

[tex]x=\sqrt{110431.825}[/tex]

X = 332.31 Ω

[tex]\text { Current }(I)=\frac{V}{R}[/tex]

[tex]\text { Current }(I)=\frac{120}{332.31}[/tex]

Current (I) = 0.361 amps

“Real power” is only consumed in the resistor,  

[tex]\mathrm{I}^{2} \mathrm{R}=0.361^{2} \times 200[/tex]

[tex]\mathrm{I}^{2} \mathrm{R}=0.1303 \times 200[/tex]

[tex]\mathrm{I}^{2} \mathrm{R}=26.06 \mathrm{Watts} \sim 26 \mathrm{watts}[/tex]

In one hour 26 watt hours are used.

Energy used in 54 hours = 26 × 24 = 624 watt hours

E = 0.624 kilowatt hours

Cost = (5)(0.624) = 3.12  

You drop a rock off a bridge. When the rock has fallen 4 m, you drop a second rock. As the two rocks continue to fall, what happens to their velocities?

a. Both increase at the same rate.
b. The velocity of the first rock increases faster than the velocity of the second.
c. The velocity of the second rock increases faster than the velocity of the first.
d. Both velocities stay constant.

Answers

Answer:

option A.

Explanation:

The correct answer is option A.

Two rocks are off a bridge first rock is fallen 4  when the second rock is dropped.

Both the rock is dropped under the effect of acceleration due to gravity so, the rate of change of the velocity for both the rock particle will be the same.

Hence, the first rock will reach ground earlier than the second rock because the rate of change of both the rock is at the same rate.

At the time when the two rocks should continue to fall so their velocities should be increased.

The correct answer is option A.

Velocity:

When two rocks are off a bridge so here first rock is fallen 4 at the time when the second rock should be fallen. Both the rock should be fallen under the impact of acceleration because of gravity due to which the rate of change of the velocity for both the rock particle should be similar.

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You are lying in bed and want to shut your bedroom door. You have a bouncy "superball" and a blob of clay, both with the same mass. Which one would be more effective to throw at your door to close it?

a. The superball.
b. Neither will work.
c. The blob of clay.
d. Both the same.

Answers

Answer:

Choice A. The bouncy "superball" will exert approximately twice as much force than the blob of clay when tossed out at the same speed.

Explanation:

The momentum of an object is equal to the product of its mass and its velocity. The momentum of the system is conserved even if the collision is inelastic.

When the bouncy ball or the blob of clay hits the door, their momentum changes. Since momentum is conserved, the door would move in the opposite direction such that the total momentum stays at zero.

Let the mass of each object be [tex]m[/tex]. Suppose that both objects hit the door at a speed of [tex]v[/tex] in the same direction.

The bouncy ball will likely bounce back at about the same speed (in the opposite direction, away from the door.) The magnitude of the change in velocity will be at most [tex]2v[/tex]. The magnitude of the change in momentum will be at most [tex]2 \,m\cdot v[/tex].However, when the blob of clay hits the door, its shape would change (and it would potentially stick to the door.) In other words, its velocity becomes almost [tex]0[/tex] after the collision. The magnitude of the change in its momentum will only be around [tex]m \cdot v[/tex], which is only about [tex]\dfrac{1}{2}[/tex] the momentum change due to the bouncy ball.

By Newton's Second Law, the net force on the door is proportion to the rate of change in its momentum. Assume that the two objects are in contact with the door for the same amount of time, the bouncy ball would exert about twice as much force on the door as the clay would. Hence it is "more effective" for closing the door.

Final answer:

The clay is more effective than the superball for shutting the door because upon impact the clay sticks to the door and transfers all of its momentum to it, while the superball bounces back and doesn't transfer all of its momentum.

Explanation:

The most effective object to throw at your door to shut it would be c. The blob of clay. This is because of the principle of conservation of momentum. When the clay hits the door, it sticks to it, thus transferring all of its momentum to the door. This momentum is what causes the door to move and potentially close. On the other hand, when the superball hits the door, it bounces back, meaning not all of its momentum is transferred to the door. Hence, the clay, by virtue of its ability to stick and transfer its full momentum, would be more effective.

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Four students use different instruments to measure the length of the same pen. Which measurement implies the greatest precision?
a. 16.0 cm.
b. 0.160 m.
c. 0.00016 km.
d. Need more information.
e. 160.0 mm

Answers

Answer:

e. 160.0 mm

Explanation:

Precision is defined as the accuracy in measurement that the measuring instrument measure any given specimen. The instrument having the lowest least count will be more precise than the instrument with higher least count.

Also precision of the reading is given by the number of the significant figures in the given sample of reading.

Option (e) that is 160.0 has a total number of significant figure of 4, which is the largest total significant figures among the other options.

Also the measurement reads 160.0 mm which measure to the lowest possible measurement of the given pen. Thus this reading is more precise.

Hence the correct option is --- Option (e) 160.0 mm

A playground merry-go-round has radius 2.80 m and moment of inertia 2400 kg⋅m2 about a vertical axle through its center, and it turns with negligible friction.A child applies an 20.0 N force tangentially to the edge of the merry-go-round for 25.0 s . If the merry-go-round is initially at rest, what is its angular speed after this 25.0 s interval?

Answers

Answer:

[tex]\omega_f = 0.602\ rad/s[/tex]

Explanation:

given,

radius of merry- go- round = 2.80 m

moment of inertia = I = 2400 kg⋅m²

child apply force tangentially = 20 N

for time = 25 s

angular speed after 25 speed = ?

initial angular speed of the merry go round = 0 rad/s

we know,

torque = I α.............(1)

α is angular acceleration

and also

τ = F.r........................(2)

computing equation (1) and (2)

F . r = I α

[tex]\alpha = \dfrac{\omega_f - \omega_i}{t}[/tex]

[tex]F . r =I \times \dfrac{\omega_f - \omega_i}{t}[/tex]

[tex]20 \times 2.89 =2400\times \dfrac{\omega_f -0}{25}[/tex]

[tex]\omega_f = 0.602\ rad/s[/tex]

the angular speed of merry-go-round after 25 second is equal to [tex]\omega_f = 0.602\ rad/s[/tex]

Consider the amideanion.What is the central atom? Enter its chemical symbol.How many lone pairs are around the central atom?What is the ideal angle between the nitrogen-hydrogen bonds?Compared to the ideal angle, you would expect the actual angle between the nitrogen-hydrogen bonds to be ...

Answers

Answer:

a) The central atom of the amide ion is nitrogen

b) (NH2)-

c) There are two lone pairs around the nitrogen atom

d) The ideal angle between nitrogen hydrogen bonds is 109.5° C, typical of a tetrahedral electron density arrangement

e) I would expect the nitrogen-hydrogen bond angles in the amide ion to be less than 109.5 ° because unbonded pairs repel bonded pairs much more than other bonded pairs do. So the bonds in this ion would be pushed closer together than normal

A 191 191 kg sculpture hangs from a horizontal rod that serves as a pivot about which the sculpture can oscillate. The sculpture's moment of inertia with respect to the pivot is 17.2 17.2 kg·m2, and when it is swung at small amplitudes, it is found to oscillate at a frequency of 0.925 0.925 Hz. How far is the pivot from the sculpture's center of mass?

Answers

Answer:

r = 0.31 m

Explanation:

Given that,

Mass of the sculpture, m = 191 kg

The sculpture's moment of inertia with respect to the pivot is, [tex]I=17.2\ kg-m^2[/tex]

Frequency of oscillation, f = 0.925 Hz

Let r is the distance of the the pivot from the sculpture's center of mass. The frequency of oscillation is given by :

[tex]f=\dfrac{1}{2\pi}\sqrt{\dfrac{mgr}{I}}[/tex]

[tex]r=\dfrac{4\pi^2f^2I}{mg}[/tex]

[tex]r=\dfrac{4\pi^2\times 0.925^2\times 17.2}{191\times 9.8}[/tex]

r = 0.31 m

So, the pivot is 0.31 meters from the sculpture's center of mass. Hence, this is the required solution.

An applied force of 122 N is exerted horizontally on an 28 kg box of dogs in Yulin. The coefficient of kinetic friction between the floor and the box is 0.35. If the box is initially at rest, what is the final kinetic energy after it has been moved 9.46 m across the floor?

Answers

Answer:

The final kinetic energy is 242 J.

Explanation:

Hi there!

According to the work-energy theorem, the total work done on the box is equal to its change in kinetic energy:

W = ΔKE

Where:

W = work done on the box.

ΔKE = change in kinetic energy (final KE - initial KE).

The only forces that do work in this case are the applied force and the friction force because the box moves only horizontally.

The equation of work is the following:

W = F · s

Where:

F = force.

s = traveled distance.

Then, the work done by the applied force is:

W = 122 N · 9.46 m = 1.15 × 10³ J

To calculate the work done by friction, we have to find the friction force:

Fr = N · μ

Where:

Fr = friction force.

N = normal force.

μ = coefficient of kinetic friction.

The box does not have a net vertical acceleration. It means that the sum of the vertical forces acting on the box is zero:

∑Fy = 0

In this case, the only vertical forces are the weight of the box and the normal force. Then:

Weight + N = 0

N = - Weight

The weight of the box is calculated as follows:

Weight = m · g

Where:

m = mass of the box.

g = acceleration due to gravity.

Then:

-Weight = N = 28 kg · 9.8 m/s² = 274.4 N

Now, we can calculate the friction force:

Fr = N · μ

Fr = 274.4 N · 0.35 = 96 N

The work done by the friction force will be:

W = Fr · s

W = 96 N · 9.46 m = 908 J

Since the work done by friction opposes to the sense of movement, the work is negative.

Now, we can calculate the total work done on the box:

W total = W applied forece + W friction force

W = 1.15 × 10³ J - 908 J = 242 J

Applying the work-energy theorem:

W = final KE - initial KE

Since the box is initially at rest the initial kinetic energy is zero. Then:

W = final KE - 0

W = final KE

Final KE = 242 J

The final kinetic energy is 242 J.

Imagine that you have obtained spectra for several galaxies and have measured the observed wavelength of a hydrogen emission line that has a rest wavelength of 656.3 nanometers. Here are your results:Galaxy 1: Observed wavelength of hydrogen line is 660.0 nanometers.Galaxy 2: Observed wavelength of hydrogen line is 665.8 nanometers.Galaxy 3: Observed wavelength of hydrogen line is 682.7 nanometers.Calculate the redshift, z, for each of these galaxies.

Answers

Answer:

Galaxy 1:

z = 0.0056

Galaxy 2:

z = 0.014

Galaxy 3:

z = 0.040

Explanation:

Spectral lines will be shifted to the blue part of the spectrum¹ if the source of the observed light is moving toward the observer, or to the red part of the spectrum when is moving away from the observer (that is known as the Doppler effect). The source in this particular case is represented for each of the galaxies of interest.

Hence, the redshift represents this shift of the spectral lines to red part in the spectrum of a galaxy or any object which is moving away. That is a direct confirmation of how the universe is in an expanding accelerated motion.

The redshift can be defined in analytic way by means of the Doppler velocity:

[tex]v = c\frac{\Delta \lambda}{\lambda_{0}}[/tex]  (1)

Where [tex]\Delta \lambda[/tex] is the wavelength shift, [tex]\lambda_{0}[/tex] is the wavelength at rest, v is the velocity of the source and c is the speed of light.

[tex]v = c(\frac{\lambda_{measured}-\lambda_{0}}{\lambda_{0}})[/tex]

[tex]\frac{v}{c} = \frac{\lambda_{measured}-\lambda_{0}}{\lambda_{0}}[/tex]  

[tex]z = \frac{\lambda_{measured}-\lambda_{0}}{\lambda_{0}}[/tex]  (2)

Where z is the redshift.

For the case of Galaxy 1:

Where [tex]\lambda_{measured} = 660.0 nm[/tex] and [tex]\lambda_{0} = 656.3 nm[/tex].

[tex]z = \frac{\lambda_{measured}-\lambda_{0}}{\lambda_{0}}[/tex]

[tex]z = (\frac{660.0 nm - 656.3 nm}{656.3 nm})[/tex]

[tex]z = 0.0056[/tex]

For the case of Galaxy 2:

Where [tex]\lambda_{measured} = 665.8 nm[/tex] and [tex]\lambda_{0} = 656.3 nm[/tex].

[tex]z = \frac{665.8 nm - 656.3 nm}{656.3 nm}[/tex]

[tex]z = 0.014[/tex]

For the case of Galaxy 3:

       

Where [tex]\lambda_{measured} = 682.7 nm[/tex] and [tex]\lambda_{0} = 656.3 nm[/tex].

[tex]z = \frac{682.7 nm - 656.3 nm}{656.3 nm}[/tex]

[tex]z = 0.040[/tex]

Key terms:

¹Spectrum: Decomposition of light in its characteristic colors (wavelengths).

Suppose that a simple pendulum consists of a small 81 g bob at the end of a cord of negligible mass. If the angle θ between the cord and the vertical is given by θ = (0.068 rad) cos[(9.2 rad/s) t + φ], what are (a) the pendulum's length and (b) its maximum kinetic energy?

Answers

Answer:

(a) 0.115 m

(b) 2.08 x 10^-5 J

Explanation:

mass of bob, m = 81 g = 0.081 kg

The equation of oscillation is given by

θ = 0.068 Cos {9.2 t + Ф}

Now by comparison

The angular velocity

ω = 9.2 rad/s

(a) [tex]\omega^{2} =\frac{g}{L}[/tex]

where, L be the length of the pendulum

[tex]L =\frac{g}{\omega ^{2}}[/tex]

[tex]L =\frac{9.8}{9.2 \times 9.2}[/tex]

L = 0.115 m

(b) A = L Sinθ

A = 0.115 x Sin 0.068

A = 7.8 x 10^-3 m

Maximum kinetic energy

K = 0.5 x mω²A²

K = 0.5 x 0.081 x 9.2 x 9.2 x 7.8 x 7.8 x 10^-6

K = 2.08 x 10^-5 J

Other Questions
Which of the following is not true about the anatomy of the urinary system?a.The right kidney is located more inferiorly than the left kidney.b.The kidneys are retroperitoneal.c.The urethra of males is longer than the urethra of females.d.The kidneys are at equal heights within the pelvic cavity.e.The ureters connect the kidneys to the urinary bladder. If you are competing for your party's nomination for the U.S. House of Representatives, you must first participate in __________ election. Our two intrepid relacar drivers are named Pam and Ned. We use these names to make it easy to remember: measurements made by Pam are primed (x', t') and those made by Ned are not primed (x, t). v is the velocity of Pam (the other frame of reference) as measured by Ned. What is the interpretation of v'?There are 4 possible choices for this answer:a. The velocity of Pam as measured by Ned.b. The velocity of Pam as measured by Pam. c. The velocity of Ned as measured by Ned.d. The velocity of Ned as measured by Pam. Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar. The function below represents the monthly expenses for an event planning company where f(x) represents the total monthly expenses for planning x events. If at the end of one month the expenses for the company were $12,350, then ___ events were plannedf(x) = 50(2x=1) + 300 In order to play at the Cape Gerbil City Miniature Golf Club, a player has to pay the membership fee and pay for each round played. The total cost is represented by the functionT = 33.47r + 17.72, where T = the total cost (in dollars) and r = the number of rounds played.Which of the following statements must be true?A .The slope is the cost per round $33.47, and the y-intercept is the membership fee of $17.72. B.The total cost is $51.19. C.The slope is the cost per round $17.72, and the y-intercept is the membership fee of $33.47. D.The slope is the membership fee of $17.72, and the y-intercept is the number of rounds played. E.I don't knowPlease answer Solve the system by elimination. 4x=3y10 9x+2y=6 Aminoglycosides: Select one: a. attach to the 30S ribosomal subunit and disrupt protein synthesis. b. are metabolic analogs of PABA and block folic acid synthesis. c. damage cell membranes. d. block peptidases that cross-link glycan molecules. Island Home Goods pursues a related diversification strategy, deriving less that 70 percent of revenues from its original business unit, Island Furniture, and maintaining several related units including Island Lighting and Island Hardware. Which of the following structures is most likely to support this strategy?A. M-Form with centralized decision-making power (cooperative multidivisional)B. M-Form with centralized decentralized decision-making power (competitive multidivisional)C. functional with centralized decision-making powerD. functional with decentralized decision-making power can someone plsss help In the Scopes trial of 1925, attorney William Jennings Bryan pitted religion against... the government. the Constitution. personal choice. evolutionary theory. identify and explain two outcomes of the implementation of the phoenician alphabet on the mediterranean region leading up to the collapse of the bronze age. The angle measurements in the diagram are represented by the following expressions.Solve for X then find the measurement of B: 11. Jillian needs to make a group of 5 people. She has 10 Democrats, 13 Republicans, and 7 Independents to choose from. (a) What is the probability that the group of 5 people will have 2 Democrats, 2 Republicans, and 1 Independent The thermosphere is: 1. the layer of atmosphere closest to the Earths surface where weather occurs. 2. supports long distance communication because it reflects outgoing radio waves back to Earth without the use of satellites. 3. the layer where auroras form when electrically charged particles from the sun collide with gas molecules releasing energy visible as light of different colors Mr. Anderson drove 168 miles in 3 hours. He then drove the next 2 hours at a rateof 5 miles an hour faster than the first rate,How many miles did Mr. Anderson drive during thhours? Supreme Court chief justice John Marshall used the Court to strengthen the judiciary and made legal decisions not explicitly discussed by the Constitution. These actions demonstrated Marshall's use of judicial:_________ In stage direction, what is the location between two other locations called What happens to the energy that is stored in cells? Check all that apply.A: It is released slowly.B: It is released quickly.C: It is released in a single reaction.D: It is released in a series of reactions.E: It is used by cells for repair and growth. This is worth 20 points. solve for w: -5(3-w)+4=-5/6(24-6w) 3x + 2 = x + 4 ( x + 2 )