Answer:
The effective molar mass of air at STP is 28.82 g/mol.
Explanation:
At STP, the value of pressure is 1 atm.
At STP, the temperature is equal to 273.15 K
P = 1atm, T = 273.15 K
Density of the gas at STP ,d= 1.285 g/L
[tex]PV=nRT[/tex] (Ideal gas equation)
[tex]PV=\frac{\text{Mass of air}}{\text{Molar mass of air(M)}}RT[/tex]
[tex]Density=\frac{Mass}{Volume}[/tex]
[tex]P\times M=d\times RT[/tex]
[tex]M=\frac{1.285 g/L}{1 atm}\times 0.0821 atm L/mol K\times 273.15 K[/tex]
M = 28.81 g/mol
The effective molar mass of air at STP is 28.82 g/mol.
Final answer:
The effective molar mass of air at standard temperature and pressure (STP), given its density of 1.285 g/L, is approximately 28.8 g/mol. This value is a weighted average based on the major components of air, mainly nitrogen and oxygen.
Explanation:
If air at STP has a density of 1.285 g/L, its effective molar mass is determined using the density and the ideal gas law. Given in the discussion, the effective molar mass of dry air is approximately 28.8 g/mol. This effective molar mass is a weighted average of the major components of air, primarily nitrogen (N₂) and oxygen (O₂), which account for about 80% and 20% of air's composition, respectively. At standard temperature and pressure (STP), 1 mole of any gas occupies 22.4 L. Therefore, the molar mass can be related to the density of the gas at these conditions to find its effective molar mass.
Using the information provided and considering the average composition of air, the calculation confirms that the effective molar mass of air at STP, considering its density of 1.285 g/L, is closely approximated to be 28.8 g/mol. This value is essential for various calculations in chemistry and environmental science, including converting between the mass of air and the number of moles of air, which is useful in stoichiometric calculations and understanding the behavior of gases under different conditions.
The A-36 steel bolt is tightened within a hole so that the reactive torque on the shank AB can be expressed by the equation t = (kx2) N.m/m, where x is in meters. If a torque of T = 50 N.m is applied to the bolt head, determine the constant k and the amount of twist in the 50-mm length of the shank. Assume the shank has a constant radius of 4 mm. The shear modulus of elasticity for A-36 steel is 75 GPa.
Answer:[tex]k=1.2\times 10^6 N/m^2,\theta =3.56^{\circ}[/tex]
Explanation:
Given
[tex]t=kx^2 Nm/m[/tex]
And a torque of 50 N.m is applied thus
[tex]T=\int_{0}^{0.05}kx^2dx[/tex]
[tex]50=\frac{1}{3}\left [ 5\times 10^{-2}\right ]^3[/tex]
[tex]k=1.2\times 10^6 N/m^2[/tex]
T at a distance x is given
[tex]T=\int_{0}^{x}1.2\times 10^6x^2dx[/tex]
[tex]T=0.4\times 10^6.x^3[/tex]
For Angle of twist
[tex]\theta =\frac{TL}{GJ}[/tex]
[tex]J=\frac{\pi d^4}{32}[/tex]
[tex]J=\frac{\pi \times 8^4\times 10^{-12}}{32}=0.402176[/tex]
G=75 GPa
[tex]\theta =\int_{0}^{0.05}\frac{\left ( 50-0.4\times 10^6x^3\right )}{GJ}[/tex]
[tex]\theta =3.56^{\circ}[/tex]
Final answer:
To find the constant k and the twist in the shank of the bolt, we equate the applied torque to the reactive torque equation, yielding k = 20,000 N.m/m^3. Then, using the shear modulus of A-36 steel, polar moment of inertia formula for circular cross-sections, and shear strain formula, we calculate the shear deformation.
Explanation:
To determine the constant k and the amount of twist in the shank AB, we first must understand that the torque T is the reactive torque on the shank due to its tightening, which is given by t = (kx2) N.m/m. Considering that the torque applied to the bolt head is T = 50 N.m, and the length of the shank x is 0.05 m (converting 50 mm to meters), we can set these values equal to find the constant k.
The shear deformation in the shank can be determined using the shear modulus (G), which is a material property indicative of the steel's rigidity. Given the shear modulus for A-36 steel is 75 GPa, and using the formula for shear strain γ = t/G, where t is the shear stress (related to torque T and the radius r), we can calculate the amount of twist in the shank.
First, we find k using T = kx2, which yields 50 N.m = k(0.05 m)2, solving for k gives us k = 20,000 N.m/m3.
Next, we calculate the shear stress t using the polar moment of inertia for a circular cross-section J = πr4/2, and shear strain using γ = tL/JG where L is the length of the shank. Substituting the given values including the radius r in meters gives us the shear deformation or twist in the shank.
A block of mass m attached to a horizontally mounted spring with spring constant k undergoes simple harmonic motion on a frictionless surface. How would the maximum speed of the block be affected if the spring constant was increased by a factor of 4 while holding the amplitude of oscillation constant?
Answer:
The maximum speed would double
Explanation:
The maximum speed of a mass-spring system is given by:
[tex]v=\omega A[/tex]
where
[tex]\omega[/tex] is the angular frequency
A is the amplitude of the motion
The angular frequency in a spring-mass system is
[tex]\omega=\sqrt{\frac{k}{m}}[/tex]
where
k is the spring constant
m is the mass
Substituting inside the first equation,
[tex]v=\sqrt{\frac{k}{m}} A[/tex]
In this problem:
- the spring constant is increased by a factor 4: k' = 4 k
- the amplitude remains constant: A' = A
So the new maximum speed would be
[tex]v'=\sqrt{\frac{4k}{m}} A= \sqrt{4} (\sqrt{\frac{k}{m}}A)= 2v[/tex]
So, the maximum speed would double.
The maximum speed of the block in simple harmonic motion is not affected by changes in the spring constant when the amplitude of oscillation is held constant.
Explanation:The maximum speed of the block in simple harmonic motion is not affected by changes in the spring constant when the amplitude of oscillation is held constant.
The maximum speed of the block is determined by the amplitude of oscillation. As long as the amplitude remains the same, increasing the spring constant by a factor of 4 will not change the maximum speed.
Therefore, the maximum speed of the block would not be affected if the spring constant was increased by a factor of 4 while holding the amplitude of oscillation constant.
Learn more about maximum speed of the block here:https://brainly.com/question/9906458
#SPJ3
Why is there condensation on the outside of my windows
While on a camping trip, a man would like to carry water from the lake to his campsite. He fills two, non‑identical buckets with water and attaches them to a 1.43 m long rod. Since the buckets are not identical, he finds that the rod balances about a point located at a 5.59 cm from its midpoint. Which bucket holds more water?
The bucket that holds more water is the bucket that is 65.9 cm from the balance point.
Principle of momentThe bucket that exerts the greatest force will be determined by applying the pinciple of moment as shown below;
Let the weight of the first bucket = W1Let the weight of the second bucket = W2Let the weight of the rod = WMid point of the rod = 0.715 m|___________1.43 m_________________|
---------------------------------------------------------------
↓ Δ 5.59 cm | ↓
W1 W W2
Take moment about the pivot;
W1(0.715 - 0.0559) = W(0.0559) + W2(0.715 + 0.0559)
W1(0.659) = W(0.0559) + W2(0.771)
Since the weight of the first bucket balances the weight of the rod and theb second bucket, the weight of the first bucket is the greatest.
Thus, the bucket that holds more water is the bucket that is 65.9 cm from the balance point.
Learn more about principle of moment here: https://brainly.com/question/26117248
The bucket that holds more water is on the side of the rod that is closer to the balance point. This is because the weight of the water is causing a greater torque on that side, pulling the balance point towards it.
Explanation:This problem relates to the principle of torque and balance. The total torque on an object is the sum of each individual torque, and when a system is in equilibrium, the total torque is zero. The torque caused by a force is calculated by multiplying the force by the distance it is from the pivot.
In this scenario, the man is balancing a long rod with two non-identical water-filled buckets. The rod is balancing off-center, indicating that the system is unbalanced and more weight is on one side. The bucket that holds more water is on the side of the rod that is closer to the balance point because more weight is pulling down on that side.
Given that the balance point is 5.59 cm from the midpoint of the 1.43m rod, the side that has the balance point nearer to the mid-point is experiencing a higher force - meaning it contains the bucket with more water.
Learn more about Torque here:https://brainly.com/question/25708791
#SPJ3
One advantage of conventional natural gas as an energy resource is its ________ .
Answer: easy transportation
Explanation:
Natural gas, after being extracted from the ground, can be sent from one place to another, wether by long gas pipelines or by large methane vessels after having gone through the liquefaction process (pass it to the liquid state).
It should be noted that in the case of transport by these vessels, it has the advantage of the possibility of ramifying the distribution without being limited to the location of the gas pipelines.
A battery-operated car utilizes a 12.0 V system. Find the charge (in C) the batteries must be able to move in order to accelerate the 850 kg car from rest to 25.0 m/s, make it climb a 2.30 ✕ 102 m high hill, and then cause it to travel at a constant 25.0 m/s by exerting a 4.00 ✕ 102 N force for an hour.
Answer:
The required charge is 3.175 × 10⁶ C
Explanation:
Given:
Potential difference, ΔV = 12.0 V
mass of the car (m) = 850 kg
velocity of the car, v = 25.0 m/s
Height of the hill upto which car traveled, h = 2.3 × 10² m = 230 m
Now, the energy required to accelerate the car from rest to 25 m/s will be
E₁ = kinetic energy of the car = [tex]\frac{1}{2}mv^2[/tex]
on substituting the values we get
E₁ = [tex]\frac{1}{2}850\times 25^2[/tex]
or
E₁ = 2.65 × 10⁵ J
Now, the potential energy gained by the car at the height 'h' will be
E₂ = mgh = 850 × 9.8 × 230 = 1.91 × 10⁶ J
Also, the energy required to make the car travel at the constant speed of 25.0 m/s with the force of 4 × 10² N for an hour will be
W = Force × displacement
now, the displacement will be = velocity × time = 25 m/s × 1hr = 25 × 3600 = 90000 m [as 1 hr = 3600 seconds]
substituting in the above equation, we get
W = 4.0 × 10² N × 90000 m = 36 × 10⁶ J
Now, the electric potential energy (ΔU) is given as:
ΔU = qΔV
where, q is the charge
Now this electric potential energy is required to do all the work in the above cases
thus,
ΔU = E₁ + E₂ + W
or
qΔV = E₁ + E₂ + W
on substituting the values in the above equation, we get
q × 12 = 2.65 × 10⁵ J + 1.91 × 10⁶ J + 36 × 10⁶ J
or
q = (3.81 × 10⁷)/12
or
q = 3.175 × 10⁶ C
Hence, the required charge is 3.175 × 10⁶ C
Two equal mass balls (one red and the other blue) are dropped from the same height, and rebound off the floor. The red ball rebounds to a higher position. Which ball is subjected to the greater magnitude of impulse during its collision with the floor?
Answer:
Red ball
Explanation:
Two ball of equal mass when fall on the surface from the same height means that both balls have same potential energy.
when the ball collides with the floor both ball posses same velocity.
but according to the statement given that red ball rebounds higher position means that the change of the velocity of the red ball is more the blue ball.
so, the change in momentum of the red ball is more than the blue ball which means the impulse during collision of the red ball will be more.
A projectile is defined as: (A) any object that is in flight.(B) any object that moves through air or space solely under the influence of gravity.(C) any object that applies an upward force to oppose gravity as it travels through air or space.
Answer:
B. Any object that moves through air or space solely under the influence of gravity.
Explanation:
Once it is dropped it continues in motion by it's own inertia and is influenced only by the downward force of gravity.
Final answer:
The correct definition of a projectile is any object that moves through air or space solely under the influence of gravity. Projectile motion involves an object launched into the air, only affected by gravity, with its horizontal and vertical motions being independent. A projectile's path is termed its trajectory, with its peak called the maximum height, and the distance covered called the range.
Explanation:
A projectile is best defined as (B) any object that moves through air or space solely under the influence of gravity. This definition eliminates any objects that are powered by engines or propellers after launch, such as rockets, and instead includes objects like balls thrown in sports, bullets fired from a gun, or rocks thrown into the air.
Once a projectile is in motion, it is subject to what is known as projectile motion. To clarify, projectile motion is the motion of an object thrown or projected into the air, subject to only the acceleration of gravity. The initial force that causes the projectile to move is disregarded after launch, and the only force acting on the projectile is the force of gravity pulling it downwards.
Properties of projectile motion are important when studying the physics behind these objects. When a projectile is in flight, its horizontal and vertical motions are independent of one another. This means that the projectile's horizontal velocity remains constant (ignoring air resistance), while the vertical velocity changes due to the acceleration of gravity. The trajectory of a projectile is its path through the air, and is typically a curved shape due to the influence of gravity. The maximum height reached by the projectile is the highest point in its trajectory, and the range is the maximum horizontal distance it covers.
Consider a magnetic force acting on an electric charge in a uniform magnetic field. Which of the following statements are true? Check all that apply.
a. The direction of the magnetic force acting on a moving electric charge in a magnetic field is perpendicular to the direction of motion.
b. The direction of the magnetic force acting on a moving charge in a magnetic field is perpendicular to the direction of the magnetic field.
c. A magnetic force is exerted on an electric charge moving through a uniform magnetic field.
d. An electric charge moving parallel to a magnetic field experiences a magnetic force.
e. A magnetic force is exerted on a stationary electric charge in a uniform magnetic field.
g. An electric charge moving perpendicular to a magnetic field experiences a magnetic force.
Answer:
The real answers are: A, B, C, G
Explanation:
The wrong answers are: D and E
D: the magnetic force (Fm) is canceled if the Speed (V) is parallel to the direction of the magnetic field (B)
E: if there is no Speed (V) there is no Force (Fm). F = q₀*v*B
q₀= electric charge
Final answer:
In a uniform magnetic field, the magnetic force acts on moving electric charges perpendicular to both their motion and the field itself, but not on stationary charges or those moving parallel to the field.
Explanation:
Considering a magnetic force acting on an electric charge in a uniform magnetic field, we find that the following statements are true:
a. The direction of the magnetic force acting on a moving electric charge in a magnetic field is perpendicular to the direction of motion.
b. The direction of the magnetic force acting on a moving charge in a magnetic field is perpendicular to the direction of the magnetic field.
c. A magnetic force is exerted on an electric charge moving through a uniform magnetic field.
g. An electric charge moving perpendicular to a magnetic field experiences a magnetic force.
Conversely, statements d and e are inaccuracies based on physics principles. An electric charge moving parallel to a magnetic field (statement d) does not experience a magnetic force because the force is dependent on the velocity of the charge being perpendicular to the field.
Similarly, a stationary electric charge in a uniform magnetic field (statement e) experiences no magnetic force, as the force acts only on moving charges.
When electric current is flowing in a metal, the electrons are movinga. at nearly the speed of light.b. at the speed of sound in air.c. at the speed of sound in the metal.d. at none of the above speeds.e. at the speed of light.
Answer:
Option (d)
Explanation:
The electrons in a conductor moves with the drift velocity when the electric current is flowing through the conductor.
The drift velocity is due to the applied electric field across the conductor.
If 2.0 mol of gas A is mixed with 1.0 mol of gas B to give a total pressure of 1.6 atm, what is the partial pressure of gas A and B?
A) PA = 0.33 atm and PB = 0.67 atm
B) PA = 0.67 atm and PB = 0.33 atm
C) PA = 1.0 atm and PB = 2.0 atm
D) PA = 2.0 atm and PB = 1.0 atm
E) PA = 1.06 atm and PB = 0.53 atm
Answer:
The partial pressure of gas A and B is option E) PA = 1.06 atm and PB = 0.53 atm
Explanation:
The pressure exerted by a particular gas in a mixture is known as its partial pressure. Then, Dalton's law states that the total pressure of a gas mixture is equal to the sum of the pressures that each gas would exert if it were alone:
PT = PA + PB
Dalton's partial pressure law can also be expressed in terms of the molar fraction of the gas in the mixture. The molar fraction is a dimensionless quantity that expresses the relationship of the number of moles of a component with the number of moles of all the components present.
The molar fraction of a gas A in a gas mixture is given by:
[tex]XA=\frac{nA}{nT}[/tex]
where nA is the amount of moles of gas A and nT is the amount of total moles.
This fraction will always be less than 1.
Then in a mixture of two or more gases, the partial pressure of the gas A can be expressed as:
PA = XA * PT
In this case you know that the total pressure PT is 1.6 atm.
You also know that 2.0 mol of gas A is mixed with 1.0 mol of gas B. Then the total number of moles will be 3 (2 moles of A plus 1 mole of B). Then you can calculate the mole fraction of gas A and gas B as:
[tex]XA=\frac{2 moles}{3 moles} =\frac{2}{3}[/tex]
[tex]XB=\frac{1 moles}{3 moles} =\frac{1}{3}[/tex]
Then, the partial pressure of the gas A and the partial pressure of the gas B can be expressed as:
[tex]PA=\frac{2}{3} *1.6 atm=1.06 atm[/tex]
[tex]PB=\frac{1}{3} *1.6 atm=0.53 atm[/tex]
Finally, the partial pressure of gas A and B is option E) PA = 1.06 atm and PB = 0.53 atm
A 5.30 m long pole is balanced vertically on its tip. What will be the speed (in meters/second) of the tip of the pole just before it hits the ground? (Assume the lower end of the pole does not slip.)
Answer:
v = 17.66 m/s
Explanation:
As we know that the lower end of the pole is fixed in the ground and it start rotating about that end
so here we can say that the gravitational potential energy of the pole will convert into rotational kinetic energy of the pole about its one end
so we have
[tex]mgL = \frac{1}{2}(\frac{mL^2}{3})\omega^2[/tex]
so we have
[tex]\omega = \sqrt{\frac{6g}{L}}[/tex]
now we have
[tex]\omega = \sqrt{\frac{6(9.81)}{5.30}}[/tex]
[tex]\omega = 3.33 rad/s[/tex]
now the speed of the other tip of the pole is given as
[tex]v = \omega L[/tex]
[tex]v = (3.33)(5.30) = 17.66 m/s[/tex]
the acceleration means that for each second that passes, falling objects move 9.8 meters.
A. True
B. False
Answer:
B. False
Explanation:
An acceleration of 9.8 m/s² means the velocity increases by 9.8 m/s every second.
The approximate distance between Mars and Earth is about 1.34 × 108 miles. How many seconds would it take for TV pictures transmitted from the Viking space vehicle on Mars's surface to reach Earth? Enter your answer in scientific notation.
Answer:
Time taken from transmission = 719.61 seconds or 11.99 minutes
Explanation:
Given data:
The distance between the mars and the earth = 1.34 × 10⁸ miles
Now, converting the distance into meters
1 mile = 1.61 km = 1610 m
thus, we have
1.34 × 10⁸ miles = 1610 × 1.34 × 10⁸ m = 2.1574 × 10¹¹ m
Now, the picture will travel with the speed of light i.e 2.998 × 10⁸ m/s
also,
Time = Distance/speed
thus we have,
Time taken from transmission = (2.1574 × 10¹¹ m)/(2.998 × 10⁸ m/s)
or
Time taken from transmission = 719.61 seconds or (719.61/60 = 11.99 minutes)
The time it takes for TV pictures transmitted from the Viking space vehicle on Mars's surface to reach Earth is approximately 7.17 × 10^2 seconds.
Explanation:To calculate the time it takes for TV pictures transmitted from the Viking space vehicle on Mars's surface to reach Earth, we need to convert the distance between Mars and Earth from miles to meters. The approximate distance between Mars and Earth is 1.34 × 108 miles, which is approximately 2.15 × 1011 meters. The speed of light is approximately 3 × 108 meters per second. Dividing the distance by the speed of light, we can calculate the time it takes: 2.15 × 1011 meters / (3 × 108 meters per second) = 7.17 × 102 seconds.
Learn more about Time taken for TV pictures to travel from Mars to Earth here:https://brainly.com/question/12999483
#SPJ3
A charged particle that is moving in a static uniform magnetic fieldA) may experience a magnetic foce, but its speed will not changeB) may experience a magnetic foce, but its direction of motion will not changeC) may experience a magnetic force which will cause its speed to changeD) will always experience a magnetic force, regardless of its direction of motionE) none of the above statements are true
Answer:
A) may experience a magnetic foce, but its speed will not change
Explanation:
A charged particle moving in an uniform magnetic field experiences a force given by:
[tex]F=qvB sin \theta[/tex]
where
q is the charge of the particle
v is the velocity of the particle
B is the magnitude of the magnetic field
[tex]\theta[/tex] is the angle between the direction of v and B
From the formula we notice that:
- if the particle is moving parallel to the field, [tex]\theta=0[/tex], so force experienced by the particle is zero --> so we can exclude option D)
Moreover, the magnetic force experienced by the particle is perpendicular to the direction of motion. This means that:
- The direction of motion of the particle will change --> so we can exclude option B)
In addition, we can notice that since the magnetic force is perpendicular to the direction of motion of the particle, the work done by the force on the particle is zero: this means that the kinetic energy of the particle does not change, so the speed of the particle does not change. So we can exclude also option C, therefore the only correct option is
A) may experience a magnetic foce, but its speed will not change
Suppose an object in free fall is dropped from a building. its starting velocity is 0 m/s. whats its speed (in m/s) of the object after falling 2 seconds?
Answer:
19.6 m/s
Explanation:
If we take down to be positive, the acceleration due to gravity is 9.8 m/s².
Acceleration = change in velocity / change in time
a = Δv / Δt
9.8 m/s² = (v − 0 m/s) / 2 s
v = 19.6 m/s
The speed after 2 seconds is 19.6 m/s.
A boy and a girl are riding on a merry-go-round which is turning at a constant rate. The boy is near the outer edge, and the girl is closer to the center. Who has the greater linear velocity?
Answer:
Boy has the greater linear velocity.
Explanation:
The liner velocity in a rotatory system is defined as:
v = ω×r
where,
v is the liner velocity
ω is the angular velocity
r is the radius.
The boy is near the edge and the girl is closer to the center. The scenario is shown in the image below.
As, mentioned in question, they are turning out at a constant rate, so the angular velocities of both the boy and the girl are same.
From the above inference, it can be concluded that now the linear velocity only depends on the radius of the disc. The linear velocity is directly proportional to the distance from the center.
Thus, the greater the distance from the center, the greater the value of liner velocity.
From the question also and from the image also the distance of the boy from the center is greater than the distance of the girl from the center. That's why boy has greater linear velocity.
A series circuit has a voltage supply of 12 V and a resistor of 2.4 kΩ. How much power is dissipated by the resistor?
A. 0.005 W
B. 0.06 W
C. 2.4 kW
D. 345.6 kW
Answer:
(B) 0.06W
Explanation:
power absorbed by the resistor is given by [tex]\frac{V^2}{R}=I^2R[/tex]
Where V = voltage
R= resistance
I = current through the circuit
we have given V =12 Volt and resistance =2.4 K[tex]\Omega[/tex]
current [tex]I=\frac{V}{R}=\frac{12}{2.4\times 1000}=5\times 10^{-3}A=5mA[/tex]
power using voltage and resistance equation
[tex]p=\frac{12^2}{2.4\times 1000}=60mW[/tex] =0.06W
using current equation [tex]P=I^2R=5^2\times 12=60mW[/tex]= 0.06W
At 1 atm pressure, the heat of sublimation of gallium is 277 kJ/mol and the heat of vaporization is 271 kJ/mol. To the correct number of significant figures, how much heat is required to melt 2.50 mol of gallium at 1 atm pressure?
Answer:15 KJ
Explanation:
We have given
at 1 atm
The heat of sublimation of Gallium =277 KJ/mol
heat of vaporization of Gallium =271 KJ/mol
[tex]\Delta H=277-271=6KJ/mol[/tex]
So heat required to melt 2.50 mol of gallium at 1 atm
Heat Required=[tex]2.5\times 6=15 KJ[/tex]
So heat required to melt 2.5 mol of gallium is 15 KJ
Final answer:
The heat required to melt 2.50 mol of gallium at 1 atm pressure is 692.5 kJ.
Explanation:
To find the heat required to melt 2.50 mol of gallium, we can use the heat of fusion (also known as the heat of sublimation) of gallium. The heat of fusion is the energy required to change a substance from a solid to a liquid at its melting point. In this case, we are given that the heat of sublimation of gallium is 277 kJ/mol.
Since gallium sublimes at 1 atm pressure, it bypasses the liquid phase and turns directly from a solid to a gas. Therefore, the heat required to melt 2.50 mol of gallium is the same as the heat of sublimation.
Therefore, to the correct number of significant figures, the heat required to melt 2.50 mol of gallium at 1 atm pressure is 2.50 mol x 277 kJ/mol = 692.5 kJ.
A grinding wheel is in the form of a uniform solid disk of radius 7.00 cm and mass 2.00 kg. It starts from rest and accelerates uniformly under the action of the constant torque of 0.600 N,m that the motor exerts on the wheel. (a) How long does the wheel take to reach its final operating speed of 1 200 rev/min? (b) Through how many revolutions does it turn while accelerating?
Answer:
Part a)
[tex]t = 1.03 s[/tex]
Part b)
[tex]N = 10.3 rev[/tex]
Explanation:
Mass of the disc is given as
m = 2.00 kg
radius of the disc is given as
r = 7 cm
so moment of inertia of the disc is given as
[tex]I = \frac{1}{2}mr^2[/tex]
[tex]I = \frac{1}{2}(2)(0.07)^2[/tex]
[tex]I = 4.9 \times 10^{-3} kg m^2[/tex]
Now given that torque on the disc is
[tex]\tau = 0.600 Nm[/tex]
so here the angular acceleration is given as
[tex]\alpha = \frac{\tau}{I}[/tex]
[tex]\alpha = \frac{0.600}{4.9 \times 10^{-3}}[/tex]
[tex]\alpha = 122.45 rad/s^2[/tex]
Part a)
if disc start from rest and then achieve final speed as 1200 rpm then
[tex]f = 1200/60 = 20 rev/s[/tex]
so final speed is
[tex]\omega = 2\pi(20) = 40\pi rad/s[/tex]
now the time taken to reach this speed is given as
[tex]\alpha t = \omega[/tex]
[tex](122.45) t = 40\pi[/tex]
[tex]t = 1.03 s[/tex]
Part b)
Number of revolution in the same time is given as
[tex]N = \frac{\omega_o + \omega}{4\pi} t[/tex]
[tex]N = \frac{40\pi + 0}{4\pi}(1.03) = 10.3 rev[/tex]
If my cylinder of air lasts 60 minutes while I am at the surface breathing normally, assuming all else is the same, how long will it last at 20 metres/66 feet breathing normally? 60 minutes
Answer:
Explanation:
Let the volume of air be V. at atmospheric pressure, that is 10⁵ Pa
At 20 m below surface pressure will be
atmospheric pressure + hdg
10⁵ + 20 x 9.8 x 1000 = 2.96 x 10⁵Pa
At this pressure volume V becomes V/ 2.96
This volume will last 1/2.96 times time that is 60/2.96 = 20.27 minutes.
Resistors R1, R2, and R3 are connected in parallel. R1 is 68 ohm and R2 is 93 ohm. The equivalent resistance of the parallel combination is 26-ohm. What is the resistance of R3?
please show work! :)
Answer:
77 Ω
Explanation:
For resistors in parallel:
1/R = 1/R₁ + 1/R₂ + 1/R₃
1/26 = 1/68 + 1/93 + 1/R₃
1/R₃ = 0.013
R₃ = 77
The resistance of R₃ is 77 Ω.
Answer:
R3=76.9 ohm
Explanation:
Hello
the equivalent resistance is given by the expression:
[tex]\frac{1}{R_{eq} } =\frac{1}{R_{1} } +\frac{1}{R_{2} }+\frac{1}{R_{3} }+...\frac{1}{R_{n} }[/tex]
we have R1=68 ohm, R=93 ohm, Rt=26 and the resistor R3 is unknown.
[tex]\frac{1}{26 } =\frac{1}{68 } +\frac{1}{93} }+\frac{1}{R_{3} }\\\frac{1}{26 } =\frac{((93*R_{3})+(68*R_{3})+(68*93)) }{68*93*R_{3} }\\26((93*R_{3})+(68*R_{3})+(68*93)) }={68*93*R_{3} }\\\\\\2418R_{3}+1768R_{3}+164424=6324R_{3}\\R_{3}(2418+1768-6324)=164424\\-2138R_{3}=-164424\\R_{3}=\frac{164424}{2138}\\ R_{3}=76.9 ohm[/tex]
Have a great day.
Flying against the wind, an airplane travels 2670 km in 3 hours. Flying with the wind, the same plane travels 11,070 km in 9 hours. What is the rate of the plane in still air and what is the rate of the wind?
Answer:
speed of plane in still air = 1060 km/h
speed of wind = 170 km/h
Explanation:
Let teh speed of plane in still air is vp and the speed of air is va.
Irt travels 2670 km in 3 hours against the wind
So,
vp - va = 2670 / 3 = 890 km/h ..... (1)
It travels 11070 km in 9 hours along the wind.
vp + va = 11070 / 9 = 1230 km/h .... (2)
Adding both the equations
2 vp = 2120
vp = 1060 km/h
and va = 1230 - vp = 1230 - 1060 = 170 km/h
Suppose a boat moves at 12.0 m/s relative to the water. If the boat is in a river with the current directed east at 2.50 m/s, what is the boat’s speed relative to the ground when it is heading (a) east, with the current, and (b) west, against the current?
Answer:
(a) 14.5 m /s
(b) 9.5 m /s
Explanation:
(a) velocity of boat with respect to water
V(b,w) = 12 i m/s
Velocity of water with respect to ground
V(w,g) = 2.5 i m/s
By the formula of relative velocity
Velocity of boat with respect to ground
V(b,g) = V(b,w) + V(w,g)
V(b,g) = 12 i = 2.5 i = 14.5 i m/s
Magnitude of velocity of boat with respect to ground = 14.5 m/s along + X axis.
(b) velocity of boat with respect to water
V(b,w) = - 12 i m/s
Velocity of water with respect to ground
V(w,g) = 2.5 i m/s
By the formula of relative velocity
Velocity of boat with respect to ground
V(b,g) = V(b,w) + V(w,g)
V(b,g) = - 12 i = 2.5 i = - 9.5 i m/s
Magnitude of velocity of boat with respect to ground = 9.5 m/s along - X axis.
An artificial heart valve was tested for its ability to function under extreme conditions, to a maximum flow rate of 4.00 x 10-4 m3/s. What speed would this correspond to for an average red blood cell within a blood vessel of cross-sectional area 5.00 x 10-6 m2?
Answer:
80 m/s
Explanation:
Rate of flow of blood, Volume per second = 4 x 10^-4 m^3/s
Area of blood vessel, A = 5 x 10^-6 m^2
So, Volume per second = area x velocity of blood
velocity of blood = (4 x 10^-4) / (5 x 10^-6) = 80 m/s
The speed of blood is 80 m/s.
Two buses leave a station at the same time and travel in opposite directions. One bus travels 16 km/h slower than the other. If the two buses are 848 km apart after 4 hours, what is the rate of each bus?
Answer:
Speed of one bus is [tex]114 \frac{km}{h}[/tex] and speed of another bus is [tex] 98 \frac{km}{h}[/tex]
Explanation:
Let the speeds of two buses be [tex]v_1\, and\, v_2[/tex] respectively
Since speed of one bus is 16 km/h slower than the other
Therefore [tex]v_1= v_2+16\frac{km}{h}[/tex]
Since buses are traveling in opposite directions so relative speed of buses
[tex]v_{rel}=v_1+v_2= v_2+16\frac{km}{h}+v_2=2v_2+16\frac{km}{h}[/tex]
Distance traveled , [tex]d=v_{rel}t[/tex]
=>[tex]848=4(2v_2+16)[/tex]
=>[tex]v_2=98 \frac{km}{h}[/tex]
[tex]\therefore v_1=v_2+16\frac{km}{h}=(98+16) \frac{km}{h}=114 \frac{km}{h}[/tex]
=>[tex]v_1=114 \frac{km}{h}[/tex]
Thus speed of one bus is [tex]114 \frac{km}{h}[/tex] and speed of another bus is [tex] 98 \frac{km}{h}[/tex]
Which of the following most logically completes the argument below?
Although the number of large artificial satellites orbiting the Earth is small compared to the number of small pieces of debris in orbit, the large satellites interfere more seriously with telescope observations because of the strong reflections they produce. Because many of those large satellites have ceased to function, the proposal has recently been made to eliminate interference from nonfunctioning satellites by exploding them in space. This proposal, however, is ill conceived, since _______.
(A) many nonfunctioning satellites remain in orbit for years
(B) for satellites that have ceased to function, repairing them while they are in orbit would be prohibitively expensive
(C) there are no known previous instances of satellites’ having been exploded on purpose
(D) the only way to make telescope observations without any interference from debris in orbit is to use telescopes launched into extremely high orbits around the Earth
(E) a greatly increased number of small particles in Earth’s orbit would result in a blanket of reflections that would make certain valuable telescope observations impossible
Answer:
(E) a greatly increased number of small particles in Earth’s orbit would result in a blanket of reflections that would make certain valuable telescope observations impossible
Explanation:
The trade is one strong reflection for many weak reflections (and more dangerous near-Earth space travel).
None of the answer choices except the last one has anything to do with the effect of exploding a satellite. When you are arguing that exploding a satellite is ill conceived, you need to address specifically the effects of exploding the satellite.
You have a pick-up truck that weighed 4,000 pounds when it was new. you are modifying it to increase its ground clearance. when you are finished
Final answer:
Modifying a truck to increase its ground clearance involves installing larger tires or lift kits, which raise the suspension and increase the distance between the ground and the underside of the truck. These modifications can improve off-road capability and traction, but it's important to consider the impact on handling and stability.
Explanation:
When modifying a truck to increase its ground clearance, one approach is to install larger tires or lift kits. These modifications can raise the truck's suspension and increase the distance between the ground and the underside of the truck.
By raising the ground clearance, the truck will be able to navigate rough terrains more easily without damaging the undercarriage. It can also provide better off-road capability and allow for larger tires, which can improve traction.
However, it's important to note that modifying a vehicle's suspension can affect its handling and stability. It's recommended to consult with a professional or experienced mechanic to ensure that the modifications are done safely and will not negatively impact the truck's performance.
A source emits a sound and is represented by the red dot in this map. Four people are located around the source, and the circles represent the sound wave.
As the source moves west, which person hears the highest pitch?
-person A
-person B (not correct)
-person C
-person D
Answer:
person A
Explanation:
because the sound is moving twords them
In the context of the Doppler Effect, person A will hear the highest pitch if they are located to the west of the moving sound source. The correct answer is a.
Explanation:As the source of the sound moves west, the observer who would hear the highest pitch is the one located to the west of the source, i.e., in the direction of the source's movement.
Since the source is moving towards the west, according to the Doppler Effect, the sound waves are compressed, and the wavelength is reduced in the direction of motion (west). This results in a higher frequency, which corresponds to a higher pitch, being heard by the observer in that direction.
If person A is to the west of the source, then person A will hear the highest pitch. It's important to note that person B has been indicated as not correct, hence, if person A is in the correct position relative to the westward movement of the source, person A will experience the higher pitch sound as compared to the others positioned differently.
A conducting bar rests on two parallel horizontal rails 50 cm apart forming a square area. The resistance of the bar and the rails is assumed to be constant and equal to 0.05 Ω. A uniform magnetic field 0.5 T is perpendicular to the plane of the rails. The value of the field is uniformly reduced to zero in a time of 0.1 s. What is the maximum value of the force acting on the bar during that time?
Answer:
Force = 6.25 N
Explanation:
Given:
Distance between the rails, l = 50cm = 0.5m
since it is forming a square area. thus, area = 0.5² m²
Resistance of the bar = 0.05Ω
Magnetic field, B = 0.5T
Time = 0.1s
Now,
The value for EMF is given as
EMF = (ΔArea x Field) /time
substituting the values in the above equation we get
EMF = (0.5² x 0.5) /0.1 = 1.25 Volts
now,
Current, i = EMF/ Resistance
substituting the values in the above equation we get
i = 1.25/0.05 = 25 A
Now the force is given as:
Force = i x l x B
Force = 25 x 0.5 x 0.5
Force = 6.25 N