U. A hockey player takes a slap shot at a puck at rest on
the ice. The puck glides over the ice for 10 ft without
friction, at which point it runs over rough ice. The
puck then accelerates opposite its motion at a uniform
rate of - 20 ft/s2. If the velocity of the puck is 40 ft/s
after traveling 100 ft from the point of impact,
(a) what is the average acceleration imparted to the
puck as it is struck by the hockey stick? (Assume that
the time of contact is 0.01 s.) (b) How far in all does
the puck travel before coming to rest? (c) What is the total time the puck is in motion, neglecting contact time?

Answers

Answer 1

Answer:

a) 7200 ft/s²

b) 140 ft

c) 3.7 s

Explanation:

(a) Average acceleration is the change in velocity over change in time.

a_avg = Δv / Δt

We need to find what velocity the puck reached after it was hit by the hockey player.

We know it reached 40 ft/s after traveling 90 feet over rough ice at an acceleration of -20 ft/s².  Therefore:

v² = v₀² + 2a(x − x₀)

(40 ft/s)² = v₀² + 2(-20 ft/s²)(100 ft − 10 ft)

v₀² = 5200 ft²/s²

v₀ = 20√13 ft/s

So the average acceleration impacted to the puck as it is struck is:

a_avg = (20√13 ft/s − 0 ft/s) / (0.01 s)

a_avg = 2000√13 ft/s²

a_avg ≈ 7200 ft/s²

(b) The distance the puck travels before stopping is:

v² = v₀² + 2a(x − x₀)

(0 ft/s)² = (5200 ft²/s²) + 2(-20 ft/s²)(x − 10 ft)

x = 140 ft

(c) The time the puck takes to travel 10 ft without friction is:

t = (10 ft) / (20√13 ft/s)

t = (√13)/26 s

The time the puck travels over the rough ice is:

v = at + v₀

(0 ft/s) = (-20 ft/s²) t + (20√13 ft/s)

t = √13 s

So the total time is:

t = (√13)/26 s + √13 s

t = (27√13)/26 s

t ≈ 3.7 s

Answer 2

The average acceleration or the total time will be:

(a) 7200 ft/s²(b) 140 ft(c) 3.7 s

According to the question,

Velocity,

[tex]v^2 = 40 \ ft/s[/tex]

Acceleration,

[tex]a = -20 \ ft/s^2[/tex]

(a)

As we know,

→     [tex]v^2=v_0^2+2a(x-x_0)[/tex]

By substituting the values, we get

→ [tex](40)^2=v_0^2+2(-20)(100-10)[/tex]

→     [tex]v_0^2=5200 \ ft^2/s^2[/tex]

→          [tex]= 20\sqrt{13} \ ft/s[/tex]

Now,

The average acceleration will be:

→ [tex]a_{avg} = \frac{\Delta v}{\Delta t}[/tex]

→         [tex]= \frac{20\sqrt{13}-0 }{0.01}[/tex]

→         [tex]= 2000\sqrt{13} \ ft/s^2[/tex]

→         [tex]= 7200 \ ft/s^2[/tex]

(b)

The distance will be:

→   [tex]v^2=v_0^2+2a(x-x_0)[/tex]

→ [tex](0)^2= 5200+2(-20)(x-10)[/tex]

→     [tex]0= 5200-40(x-10)[/tex]

→     [tex]x = 140 \ ft[/tex]

(c)

The time taken to travel 10 ft will be:

→ [tex]t = \frac{10}{20\sqrt{3} }[/tex]

     [tex]= \frac{\sqrt{13} }{26} \ s[/tex]

The time taken over rough ice will be:

→ [tex]v = at+v_0[/tex]

  [tex]0=-20t+20\sqrt{13}[/tex]

[tex]20t = 20\sqrt{13}[/tex]

   [tex]t = \sqrt{13} \ s[/tex]

hence,

The total time taken will be:

→ [tex]t = \frac{\sqrt{13} }{26} +\sqrt{13}[/tex]

     [tex]= \frac{27\sqrt{13} }{26}[/tex]

     [tex]= 3.7 \ s[/tex]

Thus the above answers are correct.    

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Related Questions

how much force would be needed to move a car with the mass of 100kg to an acceleration of 5m/s/s?​

Answers

Answer:

500 newton force is needed to move a car of mass 100kg to an acceleration of 5m/s/s.

Explanation:

As we know from Newton's second law of motion that force= F = m×a

=> F = 100 × 5 = 500 N

Hey:) what is a monatomic molecule?

Answers

Answer:

"mono" and "atomic" means single atom this term is used in both physics and chemistry and it applied to the gasses as a monatomic gas

Answer and Explanation:

Good Day mate!

A monatomic molecule is that some of the elements do not have a tendency to form a molecule. Which means, the molecule of an element is made up of only one atom.  Thus, there are called as Monatomic molecule.

Some common examples of monatomic molecules :

1. Helium (He)

2. Neon (Ne)

3. Argon (Ar)

4. Xenon (Xe)

What is needed to create change in a system?

Answers

An energy transfer. It could be heat or another type of energy due to chemical reactions, applied forces, diffusion etc..

Gravitational pull is determined by
-the sun and stars
-acceleration and volume
-volume and mass
-mass and distance​

Answers

Answer:

The gravitational pull is determined by the mass and distance.

Explanation:

According to Newton's law of universal gravitation

[tex]F = G\frac{m1.m2}{r^{2} }[/tex]

where F is the gravitational pull, G is gravitational constant, m₁ and m₂ are masses of bodies and r is the distance between them.

It can be seen from the above equation that F is directly proportional to the product of the masses and inversely proportional to the square of distance between them.

                      F ∝ m₁m₂

                      F ∝ 1/r²

Which of the following is a way that microwaves and x-rays are similar?
A. They both have technological uses.
B. They are both high energy waves,
C. They are both to be exposed to at high doses.
D. They are both used to transmit information.
(I’m between A and B)

Answers

Answer:

A

Explanation:

In my opinion I'm pretty sure it's A because WE DO use microwaves and x-rays as techonological uses.

Answer:

A

Explanation:

what is the best description of a wave

Answers


Wave involves transmission of energy from one point to another through a materials medium. ... Mechanical waves transfers energy through the vibration of particles of the medium through which the wave travels, while electromagnetic waves transfer energy through the vibration of electric or magnetic fields
Final answer:

A wave is a disturbance that travels through space and matter, characterized by its wavelength, frequency, and amplitude.

Explanation:

A wave is a disturbance or oscillation that travels through space and matter, transferring energy from one place to another. Waves are characterized by three main features: wavelength, frequency, and amplitude. The wavelength is the distance between two identical points on successive waves. The frequency refers to the number of wave cycles that occur in a second. The amplitude is a measure of the wave's height from the rest position.

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A bulldozer does 4,500 J of work to push a mound of soil to the top of a ramp that is 15 m high. The ramp is at an
angle of 35° to the ground. How much force did the bulldozer apply to the mound of soil? Round your answer to two
significant figures.



Its 520 N

Answers

Answer:

520 N

Explanation:

Work is the dot product of the force vector and displacement vector.

W = F · x

This means it is the product of the magnitudes of the vectors and the cosine of the angle between them.

W = F x cos θ

The displacement of the soil is 15 m up.  The force is parallel to the ramp.  So the angle between the vectors is 90° − 35° = 55°.

Plugging in the values and solving for F:

4500 J = F (15 m) (cos 55°)

F = 523 N

Rounded to two significant figures, the force is 520 N.

On a 100m straight track, Zak runs to the 80m mark in 15s. He then runs back to the 20m in 10s. He then runs to the 100m mark in 20s. Finally he runs to the 70m mark in 5s. The total distance travelled by Zak is ____ m and total displacement is ____ m.

Answers

Answer:

The total distance traveled by Zak is 250 m and total displacement is

70 m

Explanation:

Distance is a scalar quantity that represents how much ground an

object has covered during its motion

Displacement is a vector quantity that represents how far out of place

an object is, means the change in its position

Displacement = final position - initial position

The straight track is 100 m

Zak runs to the 80 m mark

That means he runs forward from zero to 80

Then his distance = 80 m

His displacement = + 80 m

He then runs back to the 20 m

That means that he runs back from 80 m to 20 m

Then his distance = 80 - 20 = 60 m

His displacement = 20 - 80 = -60 m

He then runs to the 100 m mark

That means he runs forward from 20 m to 100 m

Then his distance = 100 - 20 = 80 m

His displacement = 100 - 20 = + 80 m

Finally he runs to the 70 m mark

That means he runs back from 100 m to 70 m

Then his distance = 100 - 70 = 30 m

His displacement = 70 - 100 = - 30 m

His total distance is the sum of all distances he runs

The total distance = 80 + 60 + 80 + 30 = 250 m

His total displacements is the sum of all displacements he runs

The total displacement = (+80) + (-60) + (+80) + (-30) = + 70 m

The total distance traveled by Zak is 250 m and total displacement is

70 m

An astronaut on spacewalk floats a little to far from space station without air to push against he can’t paddle back however he is holding a hammer explain how he could use the hammer to get him back to space station l

Answers

Answer:

The astronaut can throw the hammer in a direction away from the space station. While he is holding the hammer, the total momentum of the astronaut and hammer is 0 kg • m/s. According to the law of conservation of momentum, the total momentum after he throws the hammer must still be 0 kg • m/s. In order for momentum to be conserved, the astronaut will have to move in the opposite direction of the hammer, which will be toward the space station.

Explanation:found this as a verified answer on here

Answer:

He can throw the hammer in the direction opposite to the direction he wants to travel in. The hammer will exert an equal and opposite force on him, as per Newton's third law, and this will help him move towards the space station

Explane

above

A 50 newton force is required to push a 10 kg box 30 meters across the floor. The box is then lifted up 6 meters and placed on a shelf. How much total work was done?

Answers

Answer:

2088 J

Explanation:

Work = net force × distance

When the box is being pushed across the floor, the force is 50 N, and the distance is 30 m.

W = (50 N) (30 m)

W = 1500 J

When the box is being lifted, the force is the weight of the box (10 kg × 9.8 m/s²), and the distance is 6 m.

W = (98 N) (6 m)

W = 588 J

So the total work done is:

W = 1500 J + 588 J

W = 2088 J

Which of the following do you calculate
when you divide the total distance trav-
eled by the total travel time?​

Answers

dividing distance by time gives you speed

How does the scattering of tiny particles in the air affect the colors of the sky at sunrise and sunset

Answers

It affects the colors of the sky at sunrise and sunset because only the longer-wavelengths colors are visible.

significant digits show the _____ of measurements and calculations.

1) accuracy
2) precision

Answers

Significant digits show the precision of measurements and calculations

A block with mass m = 6 kg is sitting on a horizontal surface and not moving. The free-fall acceleration is g = 9.81 m/s2. Please answer the following questions.


a. Write an expression for the magnitude of the force of gravity Fg on the block.

b. Calculate the magnitude of the force of gravity Fg on the block in Newtons.

c. In what direction is the force of gravity in this problem?

d. What is the magnitude of the normal force FN in Newtons?

e. In what direction does the normal force act?

Answers

Answer:

a. expression for force of gravity is mg

b. Value of force of gravity is 58.86 N

c. Direction of force of gravity is downwards

d. Value of normal force is -58.86 N

e. direction of normal force is upwards.

Explanation:

Given that mass of the block [tex]m=6 kg[/tex]

acceleration due to gravity [tex]g=9.81 m/s^2[/tex]

a. Expression for force of gravity is [tex]F_g=m\times g[/tex]

b.  [tex]F_g=mg=6 \times 9.81=58.86 N[/tex]

force of gravity is [tex]58.86 N[/tex]

c. Force of gravity always acts in the downward direction.

d. Normal force[tex]F_N[/tex]  acts in the direction opposite to the weight of the block and their magnitudes are same. since the object is at  rest the upward and downward forces on the block are balanced.

[tex]F_N=-F_g=-58.86 N[/tex]

e. Normal force [tex]F_N[/tex]acts in the upwards.

Final answer:

The force of gravity on a 6 kg block is 58.86 N, acting downwards, while the normal force is 58.86 N, acting upwards, since the block is stationary on a horizontal surface.

Explanation:

Forces Acting on a Stationary Block

a. The expression for the magnitude of the force of gravity Fg on the block is given by Newton's second law of motion: Fg = m × g where m is the mass of the object and g is the acceleration due to gravity.

b. To calculate Fg, simply multiply the mass m by the acceleration due to gravity g: Fg = 6 kg × 9.81 m/s² which equals 58.86 N.

c. In this problem, the direction of the force of gravity is vertically downwards, towards the center of the Earth.

d. The magnitude of the normal force FN on the block is equal to the force of gravity acting on the block when it is stationary on a horizontal surface, therefore FN = 58.86 N.

e. The normal force acts in a direction perpendicular to the surface, which in this case is vertically upwards.

19) Suppose that a car traveling to the east (+x direction) begins to slow down as it approaches a traffic
light. Which statement concerning its acceleration must be correct?
A) Its acceleration is in the -x direction.
B) Its acceleration is zero.
Its acceleration is decreasing in magnitude as the car slows down.
D) Its acceleration is in the +x direction.

Answers

Answer: C) Its acceleration is decreasing in magnitude as the car slows down.

Explanation:

According to the described situation the car's final velocity is less than its initial velocity, this means the car's velocity decreased as it slows down.

On the other hand, acceleration [tex]a[/tex] is defined as the variation of velocity in time:

[tex]a=\frac{\Delta V}{\Delta t}[/tex]  

If the car's velocity decreases, its acceleration is negative.  Hence, the acceleration is decreasing in magnitude as well.

In the context of a car slowing down while traveling east, its acceleration must be in the -x direction (towards the west) which means its acceleration is in the opposite direction of its motion, hence option A is correct.

The question concerns the acceleration of a car traveling east (considered the +x direction) as it begins to slow down when approaching a traffic light. According to the principles of physics, when an object is slowing down, its acceleration is in the opposite direction of its motion. Since the car is moving to the east and slowing down, its acceleration must be towards the west, which is the -x direction in our coordinate system. Therefore, its acceleration is in the -x direction, making the correct answer to the question Option A.

To further clarify, when a car traveling in a positive direction (to the east in this case) decelerates or slows down, it undergoes negative acceleration because the deceleration is opposite to the direction of its velocity. Hence, in the context of our coordinate system where the east is positive, the westward acceleration (slowing down) is considered negative.

In the periodic table of elements, what do all of the elements in group 2 have in common?

Answers

Answer:

The correct answer is chemical properties.

Explanation:

In a group, the chemical properties are very similar, because all the elements of the group have the same number of electrons in their last or last layers. The electronic configuration of its last layer is the same, varying only the period of the element. Alkaline earth metals are harder than alkaline metals, have brightness and are good electrical conductors; less reactive than alkalines, good reducing agents and form ionic compounds.

Have a nice day!

What will happen to an object at rest if no unbalanced forces act on it,
according to Newton's First Law?

Answers

the object will stay at rest

Explanation:

Newton's first law says that an object at rest stays at rest, and an object in motion stays in motion, until acted upon by an unbalanced force.

If there's no unbalanced force, then an object at rest will stay at rest.

can you help me??????????????????????????)?

Answers

Answer:

Velocity is a change in displacement over change in time and uses the units m/s.

Both are rates of change and can be positive or negative.

Acceleration is a change in velocity over change in time and uses the units m/s².

Explanation:

Velocity is the change in displacement over change in time, this makes it a rate of change. It can be positive or negative because it is a vector quantity. It uses the units m/s because that is a displacement unit over a time unit.

Acceleration is the change in velocity over change in time, this makes it a rate of change. It can be positive or negative because it is also a vector quantity. It uses the units m/s² (m/s/s) because that is a velocity unit over a time unit.

A car is traveling at 10m/s before it increases its speed to 30m/s for 120m. How long does it take to do this ?

Answers

Answer:

60 seconds

Explanation:

Given:

v₀ = 10 m/s

v = 30 m/s

Δx = 120 m

Find: t

Δx = ½ (v + v₀)t

120 = ½ (30 + 10) t

t = 60

It takes 60 seconds.

3. A car drives horizontally off of a cliff that is 40 meters tall and lands 65 meters from the base of
the cliff. What was the initial velocity of the car?

Answers

Answer:

23 m/s

Explanation:

First, find the time it takes for the car to fall 40 meters.

y = y₀ + v₀ t + ½ at²

0 = 40 + (0) t + ½ (-9.8) t²

0 = 40 − 4.9 t²

t = 2.89 s

Next, find the velocity needed to travel 65 meters in that time.

x = x₀ + v₀ t + ½ at²

65 = 0 + v₀ (2.89) + ½ (0) (2.89)²

v₀ = 22.75 m/s

Rounding to two significant figures, the car's initial speed was 23 m/s.

The number of neutrons is equal to the atomic number
O A True
B. False

Answers

Answer:false

Explanation:

The total number of the neutrons in a atom is the difference of mass number of the atom and its atomic number.

The number of neutrons is not equal to the atomic number. Thus the given statement is false.

What is atom?

Atom is the smallest unit of the matter consist the positive charged nucleus and the electrons which moves around it. The atom can not be divided further.

The atom of a matter is made by three elements-

1) Neutron-Neutron is the element of atom, which has zero charge.2) Proton-Proton is the element of atom, which has positive charge.3) Electron-Electron is the element of atom, which has negative charge.

The relation between the atomic number and neutrons-

The total number of the neutrons in a atom is the difference of mass number of the atom and its atomic number.

Thus total number of the neutrons in a atom is,

[tex]N=M-n[/tex]

Here, [tex]M[/tex] is the mass number of the atom and [tex]n[/tex] is the atomic number of it.

Thus, the number of neutrons is not equal to the atomic number. Thus the given statement is false.

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A nonuniform, but spherically symmetric, distribution of charge has a charge density ρ(r) given as follows:
ρ(r)=ρ0(1−r/R) for r≤R
ρ(r)=0 for r≥R
where ρ0=3Q/πR3 is a positive constant.

Express your answer in terms of some or all of the variables r, R, Q, and appropriate constants.
Obtain an expression for the electric field in the region r≥R.
Obtain an expression for the electric field in the region r≤R.
Find the value of r at which the electric field is maximum.
Find the value of that maximum field.

Answers

Answer:

r ≥ R, E = Q / (4πR²ε₀)

r ≤ R, E = 12Q (⅓ (r/R)³ − ¼ (r/R)⁴) / (4πr²ε₀)

Maximum at r = ⅔ R

Maximum field of E = Q / (3πε₀R²)

Explanation:

Gauss's law states:

∮E·dA = Q/ε₀

What that means is, if you have electric field vectors E passing through areas dA, the sum of those E vector components perpendicular to the dA areas is equal to the total charge Q divided by the permittivity of space, ε₀.

a) r ≥ R

Here, we're looking at the charge contained by the entire sphere.  The surface area of the sphere is 4πR², and the charge it contains is Q.  Therefore:

E(4πR²) = Q/ε₀

E = Q / (4πR²ε₀)

b) r ≤ R

This time, we're looking at the charge contained by part of the sphere.

Imagine the sphere is actually an infinite number of shells, like Russian nesting dolls.  For any shell of radius r, the charge it contains is:

dq = ρ dV

dq = ρ (4πr²) dr

The total charge contained by the shells from 0 to r is:

q = ∫ dq

q = ∫₀ʳ ρ (4πr²) dr

q = ∫₀ʳ ρ₀ (1 − r/R) (4πr²) dr

q = 4πρ₀ ∫₀ʳ (1 − r/R) (r²) dr

q = 4πρ₀ ∫₀ʳ (r² − r³/R) dr

q = 4πρ₀ (⅓ r³ − ¼ r⁴/R) |₀ʳ

q = 4πρ₀ (⅓ r³ − ¼ r⁴/R)

Since ρ₀ = 3Q/(πR³):

q = 4π (3Q/(πR³)) (⅓ r³ − ¼ r⁴/R)

q = 12Q (⅓ (r/R)³ − ¼ (r/R)⁴)

Therefore:

E(4πr²) = 12Q (⅓ (r/R)³ − ¼ (r/R)⁴) / ε₀

E = 12Q (⅓ (r/R)³ − ¼ (r/R)⁴) / (4πr²ε₀)

When E is a maximum, dE/dr is 0.

First, simplify E:

E = 12Q (⅓ (r/R)³ − ¼ (r/R)⁴) / (4πr²ε₀)

E = Q (4 (r³/R³) − 3 (r⁴/R⁴)) / (4πr²ε₀)

E = Q (4 (r/R³) − 3 (r²/R⁴)) / (4πε₀)

Take derivative and set to 0:

dE/dr = Q (4/R³ − 6r/R⁴) / (4πε₀)

0 = Q (4/R³ − 6r/R⁴) / (4πε₀)

0 = 4/R³ − 6r/R⁴

0 = 4R − 6r

r = ⅔R

Evaluating E at r = ⅔R:

E = Q (4 (⅔R / R³) − 3 (⁴/₉R² / R⁴)) / (4πε₀)

E = Q (8 / (3R²) − 4 / (3R²)) / (4πε₀)

E = Q (4 / (3R²)) / (4πε₀)

E = Q (1 / (3R²)) / (πε₀)

E = Q / (3πε₀R²)

For question 1:

For the region [tex]r \geq R[/tex], an expression for the electric field can be calculated by using the  Gauss law:

Use gauss law of electrostatics, the charge electric flux through the Gaussian surface is,

[tex]\int \vec{E} \cdot d\vec{A}=\frac{q_{enc}}{\varepsilon_{0} }\\\\E(4\pi r^2)=\frac{Q}{\varepsilon_0}\ \ \ \ \ \ \ \ \ \ \ \ \ (Since\ \ q_{enc}=Q )[/tex]

Here, Q is the enclosed charge and [tex]\varepsilon_0[/tex] , is the permeability.

[tex]E=\frac{1}{4\pi \varepsilon_0 } \frac{Q}{r^2}[/tex]

Therefore, the required electric field is [tex]\frac{Q}{4\pi\varepsilon_0 r^2 }[/tex]

For question 2:

For Gaussian sphere of radius [tex]r \leq R[/tex], the charge enclosed within a spherical shell is,

[tex]dq =\rho_0(1-\frac{r}{R}) 4\pi r^2 dr[/tex]

Hence, the total charge enclosed with in the radius r is as follows,  

[tex]q_{enc}=\int^{r}_{0} \rho_{0} (1-\frac{r}{R}) 4\pi r^2 \ dr\\\\[/tex]

       [tex]=4\pi \rho_0 |\frac{r^3}{3}-\frac{r^4}{4R}|^4_{0}\\\\=\frac{12 Q}{R^3}(\frac{r^3}{3}-\frac{r^3}{4R})\\\\=\frac{Qr^3}{R^3}(4-\frac{3r}{R})\\\\[/tex]

Use Gauss's law for the Gaussian sphere of radius r,

[tex]\int \vec{E}\cdot dA=\frac{q_{enc}}{\varepsilon_0}\\\\E(4\pi r^2)=\frac{Qr^3}{\varepsilon_0 R^3}(4-\frac{3r}{R})\\\\E=\frac{Qr}{4\pi \varepsilon_0 R^3}(4-\frac{3r}{R})\\\\[/tex]

Therefore, the required electric field at [tex]r\leq R[/tex] is [tex]\frac{Qr}{4\pi \varepsilon_0 R^3}(4-\frac{3r}{R})\\\\[/tex]

For question 3:

The change in electric filed with respect to distance is zero when the electric field has a  maximum value.

[tex]\frac{dE}{dr}= 0\\\\\frac{d(\frac{Qr}{4\pi \varepsilon_0 R^3}(4-\frac{3r}{R}))}{dr}=0\\\\(\frac{Q}{4\pi \varepsilon_0 R^3})\frac{d(4r-\frac{3r^2}{R})}{dr}=0\\\\[/tex]

Here, [tex](\frac{Q}{4\pi \varepsilon_0 R^3})[/tex] is not equal to zero. Hence,

[tex]\frac{d(4r-\frac{3r^2}{R})}{dr}=0\\\\4-\frac{6r}{R}=0\\\\r=\frac{4R}{6}=\frac{2R}{3}[/tex]

Therefore, the required value of [tex]r \ \ is\ \ \frac{2R}{3}\\\\[/tex]

For question 4:

Maximum value of the electric filed is as follows

[tex]E= \frac{Q}{4\pi \varepsilon_0 R^3} (4-\frac{3r}{R})\\\\[/tex]

   [tex]= \frac{Q(\frac{2R}{3})}{4\pi \varepsilon_0 R^3} (4- \frac{3(\frac{2R}{3})}{R})\\\\=\frac{Q}{3 \pi \varepsilon_0 R^2}[/tex]

Therefore, the required maximum value of the electric field is [tex]\frac{Q}{3 \pi \varepsilon_0 R^2}[/tex]

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A sailor pulls a 2,000 kilogram boat 25 meters along the dock with a rope attached to the boat that makes a 45 degree angle with the dock. How much work is done by the sailor if he exerts a force of 400 newtons while pulling the boat?

Answers

Answer: 7071.067 Joules

Explanation:

The Work [tex]W[/tex] done by a Force [tex]F[/tex] refers to the release of potential energy from a body that is moved by the application of that force to overcome a resistance along a path [tex]d[/tex].  

It should be noted that it is a scalar, and its unit in the International System of Units is the Joule (like energy). Therefore, 1 Joule is the work done by a force of 1 Newton when moving an object, in the direction of the force, along 1 meter:  

[tex]1J=(1N)(1m)=Nm[/tex]  

Now, when the applied force is constant and the direction of the force and the direction of the movement are parallel, the equation to calculate it is:  

[tex]W=(F)(d)[/tex] (1)

When they are not parallel, both directions form an angle, let's call it [tex]\alpha[/tex]. In that case the expression to calculate the Work is:  

[tex]W=Fdcos{\alpha}[/tex] (2)

In this case the force and the distance in the path form an angle [tex]\alpha=45\°[/tex], so we will use the second equation, where [tex]F=400N[/tex] and [tex]d=25 m[/tex]:

[tex]W=(400 N)(25 m) cos(45\°)[/tex] (3)

Then:

[tex]W=7071.067 Nm=7071.067 J[/tex]

The work done by the sailor to pull the boat 25 meters with a force of 400 newtons at a 45-degree angle to the dock is approximately 7,071 Joules.

The amount of work done by the sailor on the boat can be calculated by using the formula for work done by a force at an angle, which is W = F  imes d  imes  ext{cos}( heta). In this case, the force (F) is 400 newtons, the distance (d) is 25 meters, and the angle ( heta) is 45 degrees.

First, we calculate the cosine of the angle, which in this case is  ext{cos}(45^{ ext{o}}) =  rac{ ext{ extsqrt{2}}}{2}.

Then, we multiply the force, distance, and cosine of the angle: W = 400 N  imes 25 m  imes  rac{ ext{ extsqrt{2}}}{2}.

Therefore, the work done by the sailor is 400  imes 25  imes  rac{ ext{ extsqrt{2}}}{2}, which equals 7,071 Joules approximately.

Bernoulli’s principle states that fluid velocity decreases when flow is restricted. True False

Answers

True. The given statement is true

What is gas pressure

Answers

Answer:

Pressure is a force exerted by the substance per unit area on another substance. The pressure of a gas is the force that the gas exerts on the walls of its container. When you blow air into a balloon, the balloon expands because the pressure of air molecules is greater on the inside of the balloon than the outside.xplanation:

Answer:

Pressure is a force exerted by the substance per unit area on another substance. The pressure of a gas is the force that the gas exerts on the walls of its container. When you blow air into a balloon, the balloon expands because the pressure of air molecules is greater on the inside of the balloon than the outside.

Explanation:

At summer camp, the swimming course runs the length (L) of a small lake. To determine the length of the course, the camp counselors measure the two "dry" legs of a right triangle. What is the length in meters of the swimming course in the figure below? A right triangle overlaps a lake. It has sides 25 and 40 meters. Hypotenuse labeled L goes through the lake.

Answers

Answer:

The length of the swimming course is 47.16 meters.

Explanation:

It is given that the right triangle overlaps the lake and hypotenuse L runs through the length of the lake. Thus length of the lake will be the length of this hypotenuse.

The instructors have conducted measurements of the right triangle and has found the legs to be 25 and 40 meters. The sum of squares of base and height of  a right triangle gives the value of its hypotenuse according to Pythagoras theorem.

Thus [tex]h^2+b^2=H^2[/tex]

b - base

h - height.

[tex]40^2+25^2=1600+625=2225[/tex]

[tex]H=\sqrt{2225}=47.16 m[/tex]

5. A car is traveling at 100 km/hr. How many hours will it take to cover a displacement of 750 km?

Answers

Wouldn’t it be 7 and 1/2 hours (7.5)? because 750/100=7 1/2 or 7.5. that is one way to explain but i’m happy to go further

Answer:

It will take 1 hour for a car to cover a displacement of 750 km at a constant speed of 100 km / hr.

Explanation:

Velocity ​​is associated with the change of position of a body over time. In other words, speed expresses the relationship between the space traveled by an object, the time taken for it and its direction.

That is, speed implies the change of position of an object in space within a certain amount of time (that is, speed), added to the direction in which said movement occurs.

Then, 100 km / hr is the speed of the car and indicates that every hour the car travels 100  kilometres.

Then it is possible to apply a rule of three to calculate the time it takes for the car to travel 750 km. The three employee rule is: if 100 km are traveled in 1 hour, 750 km in how long is it traveled?

[tex]time=\frac{750 km*1hour}{100 km}[/tex]

time=7.5 hour

It will take 1 hour for a car to cover a displacement of 750 km at a constant speed of 100 km / hr.

How are energy of motion and speed are related to each other?

Answers

The energy transferred is known as kinetic energy, and it depends on the mass and speed achieved. Kinetic energy can be transferred between objects and transformed into other kinds of energy.

An object is thrown directly up (positive direction) with a velocity (vo) of 20.0 m/s and do= 0. How high does it rise (v = 0 cm/s at top of rise). Remember, acceleration is -9.80 m/s2.

d = _____ m

1.02
2.04
20.4
40.8

Answers

Answer:

20.4

Explanation:

Given:

y₀ = 0 m

v₀ = 20.0 m/s

v = 0 m/s

a = -9.80 m/s²

Find: y

v² = v₀² + 2a (y − y₀)

(0 m/s)² = (20.0 m/s)² + 2 (-9.80 m/s²) (y − 0 m)

y = 20.4 m

With which part of the brain is awareness typically associated?

Answers

Answer:cerebral cortex

Explanation:

Answer:

Cerebral Cortex

Explanation:

The cerebral cortex has a left and a right hemisphere. Each hemisphere can be divided into four lobes: the frontal lobe, temporal lobe, occipital lobe, and parietal lobe. The lobes are functional segments. They specialize in various areas of thought and memory, of planning and decision making, and of speech and sense perception.

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