Question 1

A force of 200 N is applied to a 50-kg mass in the direction of motion for a distance of 6.0 m,and then the force is increased to 300 N for the next 5.0 m.For the 11 m of travel,how much work is done by the varying force?

Accepted Answer

The work done is calculated by summing the work done over each segment: W = F1 * d1 + F2 * d2 = 200 N * 6 m + 300 N * 5 m = 1200 J + 1500 J = 2700 J.

Question 2

A 15.0-kg crate,initially at rest,slides down a ramp 4.0 m long and inclined at an angle of 20° with the horizontal.If there is no friction between ramp surface and crate,what is the kinetic energy of the crate at the bottom of the ramp? (g = 9.8 m/s²)

Accepted Answer

A

Question 3

A horizontal force of 100 N is applied to move a 45-kg cart across a 5.0-m level surface.What work is done by the 100-N force?

Accepted Answer

Work done by force = force x distance x cos(theta), where theta is the angle between the direction of the force and the direction of motion. In this case, theta=0 degrees, so cos(theta) = 1. 
Work = 100 N x 5.0 m x 1 = 500 J.

Question 4

Rupel pushes a box 4.00 m by applying a 25.0-N horizontal force.What work does she do?

Accepted Answer

Work is calculated as the product of force and distance in the direction of the force. Here, Work = Force x Distance = 25.0 N x 4.00 m = 100 J.

Question 5

I use a rope 1.00-m-long to swing a 1.00-kg weight around my head.The tension in the rope is 20.0 N.In half a revolution how much work is done by the rope on the weight?

Accepted Answer

The work done by the rope on the weight is zero because the tension force is always perpendicular to the direction of motion of the weight, resulting in no work being done.

Question 6

What is the minimum amount of energy required for a 70.0-kg climber carrying a 20.0-kg pack to climb Mt.Everest,which is 8850 m high?

Accepted Answer

The answer of What is the minimum amount of energy...

Question 7

The net force acting on a 12.6-kg object is given by F_x = (8 - x)N,where F_x is in newtons and x is in meters.How much work is done on the object as it moves from x = 0 to x = 6 m?

Accepted Answer

The work done on the object as it moves from x = 0 to x = 6 m is equal to the area under the force versus displacement graph.

Using the given force equation, we can find the area:

W = ∫(8-x)dx from x=0 to x=6
W = [8x - (x^2)/2] from x=0 to x=6
W = (8*6 - (6^2)/2) - (8*0 - (0^2)/2)
W = 48 - 0
W = 48 J

Therefore, the correct answer is B) 30 J.

Question 8

A satellite is held in orbit by a 3000-N gravitational force.Each time the satellite completes an orbit of circumference 80,000 km,the work done on it by gravity is:

Accepted Answer

The work done by gravity on a satellite moving in circular orbit is zero since the gravitational force is perpendicular to the direction of motion at every point of the orbit. Therefore, the correct answer is D) 0.

Question 9

What is the kinetic energy of a 0.160-kg ball thrown at 40.0 m/s (90.0 mph)?

Accepted Answer

The answer of What is the kinetic energy of a...

Question 10

A 10.0-kg box starts at rest and slides 6.0 m down a ramp inclined at an angle of 10° with the horizontal.If there is no friction between the ramp surface and crate,what is the velocity of the crate at the bottom of the ramp? (g = 9.8 m/s²)

Accepted Answer

The answer of A 10.0-kg box starts at rest and...

Question 11

A simple pendulum,2.00 m in length,is released from rest when the support string is at an angle of 35.0° from the vertical.What is the speed of the suspended mass at the bottom of the swing? (g = 9.80 m/s² and ignore air resistance)

Accepted Answer

The potential energy at the top is converted to kinetic energy at the bottom. Using conservation of energy: mgh = 0.5mv^2. The height h can be found using h = L(1 - cos(θ)). Solving for v gives v = sqrt(2gL(1 - cos(θ))), which results in approximately 2.66 m/s.

Question 12

A horizontal force of 200 N is applied to a 55-kg cart across a 10 m level surface.If the cart accelerates at 3.0 m/s²,then what is the work done by the force of friction as it acts to retard the motion of the cart?

Accepted Answer

The answer of A horizontal force of 200 N is...

Question 13

In 1908 there was a huge explosion referred to as the Tunguska event which occurred in Siberia.Apparently this was caused by a very large meteorite,a small asteroid,or a comet colliding with the Earth.If the energy released,estimated at 5 × 10¹⁶ J,were from the kinetic energy of the object,what would have been its approximate mass if its speed had been 10⁴ m/s?

Accepted Answer

The formula for kinetic energy is:
KE = 0.5 * m * v^2
where KE is the kinetic energy, m is the mass of the object, and v is the speed of the object.

Rearranging the formula to solve for mass:
m = 2 * KE / v^2

Plugging in the given values:
KE = 5 × 10^14 J
v = 10^14 m/s

m = 2 * (5 × 10^14) / (10^14)^2
m = 2 * 5 × 10^14 / 10^28
m = 10^19 kg

The closest answer choice is B, 10^19 kg.

Question 14

A rock is thrown straight up with an initial velocity of 20.0 m/s.Ignore energy lost to air friction.How high will the rock rise?

Accepted Answer

The height that the rock will reach can be found using the kinematic equation: 
Δy = v0t + (1/2)at^2 
where Δy is the change in height, v0 is the initial velocity, a is the acceleration due to gravity (-9.8 m/s^2), and t is the time it takes for the rock to reach its highest point (when its final velocity is 0 m/s). 
Using the given initial velocity, v0 = 20.0 m/s, and the fact that the final velocity at the highest point is 0 m/s, we can find the time it takes for the rock to reach its highest point: 
0 = 20.0 m/s - 9.8 m/s^2 * t_highest 
t_highest = 20.0 m/s / 9.8 m/s^2 = 2.04 s 
Plugging this into the same kinematic equation gives: 
Δy = (20.0 m/s)(2.04 s) + (1/2)(-9.8 m/s^2)(2.04 s)^2 
Δy = 20.4 m 
Therefore, the rock will reach a height of 20.4 meters.

Question 15

Samantha pushes a 60-N crate up a ramp 20.0 m in length and inclined at 10° with the horizontal.What potential energy change does the crate experience?

Accepted Answer

The answer of Samantha pushes a 60-N crate up a...

Question 16

A 5.00 kg ball falls from a 2.00 m-high shelf.Just before hitting the floor,what will be its kinetic energy? (g = 9.80 m/s² and assume air resistance is negligible)

Accepted Answer

The potential energy of the ball just before falling is given by:

PE = mgh

where m is the mass of the ball, g is the acceleration due to gravity, and h is the height of the shelf. Substituting the given values:

PE = (5.00 kg)(9.80 m/s^2)(2.00 m) = 98.0 J

When the ball hits the ground, all its potential energy is converted into kinetic energy. Therefore, the kinetic energy just before hitting the ground is also 98.0 J.

Hence, the best choice is A) 98.0 J.

Question 17

A 1200-kg automobile moving at 25 m/s has the brakes applied with a deceleration of 5.0 m/s².How far does the car travel before it stops?

Accepted Answer

The answer of A 1200-kg automobile moving at 25 m/s...

Question 18

A baseball catcher puts on an exhibition by catching a 0.15-kg ball dropped from a helicopter at a height of 91 m.What is the speed of the ball just before it hits the catcher's glove 1.0 m above the ground? (g = 9.8 m/s² and ignore air resistance)

Accepted Answer

Using the equation vf² = vi² + 2gh, we can solve for final velocity (vf):
vf² = 0 + 2(9.8 m/s²)(91 m)
vf = 42 m/s (rounded to 2 significant figures)

Therefore, the answer is C, 42 m/s.

Question 19

The net force acting on a 6.0-kg object is given by F_x = (12 - x)N,where F_x is in newtons and x is in meters.How much work is done on the object as it moves from x = 0 to x = 12 m?

Accepted Answer

The work done is the integral of force over distance. Integrating F(x) = (12 - x) from x = 0 to x = 12 gives W = ∫(12 - x) dx from 0 to 12 = [12x - (x^2)/2] from 0 to 12 = (12*12 - (12^2)/2) - (12*0 - (0^2)/2) = 144 - 72 = 72 J.

Question 20

A professional skier reaches a speed of 39.6 m/s on a 30° ski slope.Ignoring friction,what was the minimum distance along the slope the skier would have had to travel,starting from rest?

Accepted Answer

The answer of A professional skier reaches a speed of...

Quiz 6: Momentum and Collisions: Part A

A force of 200 N is applied to a 50-kg mass in the direction of motion for a distance of 6.0 m,and then the force is increased to 300 N for the next 5.0 m.For the 11 m of travel,how much work is done by the varying force?

A 15.0-kg crate,initially at rest,slides down a ramp 4.0 m long and inclined at an angle of 20° with the horizontal.If there is no friction between ramp surface and crate,what is the kinetic energy of the crate at the bottom of the ramp? (g = 9.8 m/s²)

A horizontal force of 100 N is applied to move a 45-kg cart across a 5.0-m level surface.What work is done by the 100-N force?

Rupel pushes a box 4.00 m by applying a 25.0-N horizontal force.What work does she do?

I use a rope 1.00-m-long to swing a 1.00-kg weight around my head.The tension in the rope is 20.0 N.In half a revolution how much work is done by the rope on the weight?

What is the minimum amount of energy required for a 70.0-kg climber carrying a 20.0-kg pack to climb Mt.Everest,which is 8850 m high?

The net force acting on a 12.6-kg object is given by F_x = (8 - x) N,where F_x is in newtons and x is in meters.How much work is done on the object as it moves from x = 0 to x = 6 m?

A satellite is held in orbit by a 3000-N gravitational force.Each time the satellite completes an orbit of circumference 80,000 km,the work done on it by gravity is:

What is the kinetic energy of a 0.160-kg ball thrown at 40.0 m/s (90.0 mph) ?

A 10.0-kg box starts at rest and slides 6.0 m down a ramp inclined at an angle of 10° with the horizontal.If there is no friction between the ramp surface and crate,what is the velocity of the crate at the bottom of the ramp? (g = 9.8 m/s²)

A simple pendulum,2.00 m in length,is released from rest when the support string is at an angle of 35.0° from the vertical.What is the speed of the suspended mass at the bottom of the swing? (g = 9.80 m/s² and ignore air resistance)

A horizontal force of 200 N is applied to a 55-kg cart across a 10 m level surface.If the cart accelerates at 3.0 m/s²,then what is the work done by the force of friction as it acts to retard the motion of the cart?

A rock is thrown straight up with an initial velocity of 20.0 m/s.Ignore energy lost to air friction.How high will the rock rise?

Samantha pushes a 60-N crate up a ramp 20.0 m in length and inclined at 10° with the horizontal.What potential energy change does the crate experience?

A 5.00 kg ball falls from a 2.00 m-high shelf.Just before hitting the floor,what will be its kinetic energy? (g = 9.80 m/s² and assume air resistance is negligible)

A 1200-kg automobile moving at 25 m/s has the brakes applied with a deceleration of 5.0 m/s².How far does the car travel before it stops?

A baseball catcher puts on an exhibition by catching a 0.15-kg ball dropped from a helicopter at a height of 91 m.What is the speed of the ball just before it hits the catcher's glove 1.0 m above the ground? (g = 9.8 m/s² and ignore air resistance)

The net force acting on a 6.0-kg object is given by F_x = (12 - x) N,where F_x is in newtons and x is in meters.How much work is done on the object as it moves from x = 0 to x = 12 m?

A professional skier reaches a speed of 39.6 m/s on a 30° ski slope.Ignoring friction,what was the minimum distance along the slope the skier would have had to travel,starting from rest?

Quiz 6: Momentum and Collisions: Part A

A force of 200 N is applied to a 50-kg mass in the direction of motion for a distance of 6.0 m,and then the force is increased to 300 N for the next 5.0 m.For the 11 m of travel,how much work is done by the varying force?

A 15.0-kg crate,initially at rest,slides down a ramp 4.0 m long and inclined at an angle of 20° with the horizontal.If there is no friction between ramp surface and crate,what is the kinetic energy of the crate at the bottom of the ramp? (g = 9.8 m/s2)

A horizontal force of 100 N is applied to move a 45-kg cart across a 5.0-m level surface.What work is done by the 100-N force?

Rupel pushes a box 4.00 m by applying a 25.0-N horizontal force.What work does she do?

I use a rope 1.00-m-long to swing a 1.00-kg weight around my head.The tension in the rope is 20.0 N.In half a revolution how much work is done by the rope on the weight?

What is the minimum amount of energy required for a 70.0-kg climber carrying a 20.0-kg pack to climb Mt.Everest,which is 8850 m high?

The net force acting on a 12.6-kg object is given by Fx = (8 - x) N,where Fx is in newtons and x is in meters.How much work is done on the object as it moves from x = 0 to x = 6 m?

A satellite is held in orbit by a 3000-N gravitational force.Each time the satellite completes an orbit of circumference 80,000 km,the work done on it by gravity is:

What is the kinetic energy of a 0.160-kg ball thrown at 40.0 m/s (90.0 mph) ?

A 10.0-kg box starts at rest and slides 6.0 m down a ramp inclined at an angle of 10° with the horizontal.If there is no friction between the ramp surface and crate,what is the velocity of the crate at the bottom of the ramp? (g = 9.8 m/s2)

A simple pendulum,2.00 m in length,is released from rest when the support string is at an angle of 35.0° from the vertical.What is the speed of the suspended mass at the bottom of the swing? (g = 9.80 m/s2 and ignore air resistance)

A horizontal force of 200 N is applied to a 55-kg cart across a 10 m level surface.If the cart accelerates at 3.0 m/s2,then what is the work done by the force of friction as it acts to retard the motion of the cart?

A rock is thrown straight up with an initial velocity of 20.0 m/s.Ignore energy lost to air friction.How high will the rock rise?

Samantha pushes a 60-N crate up a ramp 20.0 m in length and inclined at 10° with the horizontal.What potential energy change does the crate experience?

A 5.00 kg ball falls from a 2.00 m-high shelf.Just before hitting the floor,what will be its kinetic energy? (g = 9.80 m/s2 and assume air resistance is negligible)

A 1200-kg automobile moving at 25 m/s has the brakes applied with a deceleration of 5.0 m/s2.How far does the car travel before it stops?

A baseball catcher puts on an exhibition by catching a 0.15-kg ball dropped from a helicopter at a height of 91 m.What is the speed of the ball just before it hits the catcher's glove 1.0 m above the ground? (g = 9.8 m/s2 and ignore air resistance)

The net force acting on a 6.0-kg object is given by Fx = (12 - x) N,where Fx is in newtons and x is in meters.How much work is done on the object as it moves from x = 0 to x = 12 m?

A professional skier reaches a speed of 39.6 m/s on a 30° ski slope.Ignoring friction,what was the minimum distance along the slope the skier would have had to travel,starting from rest?

A 15.0-kg crate,initially at rest,slides down a ramp 4.0 m long and inclined at an angle of 20° with the horizontal.If there is no friction between ramp surface and crate,what is the kinetic energy of the crate at the bottom of the ramp? (g = 9.8 m/s²)

The net force acting on a 12.6-kg object is given by F_x = (8 - x) N,where F_x is in newtons and x is in meters.How much work is done on the object as it moves from x = 0 to x = 6 m?

A 10.0-kg box starts at rest and slides 6.0 m down a ramp inclined at an angle of 10° with the horizontal.If there is no friction between the ramp surface and crate,what is the velocity of the crate at the bottom of the ramp? (g = 9.8 m/s²)

A simple pendulum,2.00 m in length,is released from rest when the support string is at an angle of 35.0° from the vertical.What is the speed of the suspended mass at the bottom of the swing? (g = 9.80 m/s² and ignore air resistance)

A horizontal force of 200 N is applied to a 55-kg cart across a 10 m level surface.If the cart accelerates at 3.0 m/s²,then what is the work done by the force of friction as it acts to retard the motion of the cart?

A 5.00 kg ball falls from a 2.00 m-high shelf.Just before hitting the floor,what will be its kinetic energy? (g = 9.80 m/s² and assume air resistance is negligible)

A 1200-kg automobile moving at 25 m/s has the brakes applied with a deceleration of 5.0 m/s².How far does the car travel before it stops?

A baseball catcher puts on an exhibition by catching a 0.15-kg ball dropped from a helicopter at a height of 91 m.What is the speed of the ball just before it hits the catcher's glove 1.0 m above the ground? (g = 9.8 m/s² and ignore air resistance)

The net force acting on a 6.0-kg object is given by F_x = (12 - x) N,where F_x is in newtons and x is in meters.How much work is done on the object as it moves from x = 0 to x = 12 m?