WorksheetsWork Power NRG
Total questions: 51
Worksheet time: 1hrs 5mins
What is the potential energy of a 3kg ball that is on the ground?
0 J
3 J
9.8 J
29.4 J
Which statement illustrates work done?
A weightlifter holds a barbell above her head.
A teacher applies a force to a wall and becomes exhausted.
A rolling marble hits a note card and moves it across a table.
A waiter carries a tray full of meals across a dining room at a constant speed.
How will you describe the energy at Point A?
mostly potential energy
mostly kinetic energy
losing PE, gaining KE
losing KE, gaining PE
A block starts at rest at point P at the top of a ramp which is height h above the ground. The block slides down one side and up the other, stopping at a point less than h above the ground.
The block did not go as high on the other side because gravity pulls down.
The block did not go as high on the other side because potential energy always has to decrease.
The block did not go as high on the other side because work from friction made the mechanical energy less.
The situation as described is impossible to happen.
How does conservation of energy explain why something that is falling should speed up?
It gains kinetic energy because it gains potential energy.
It loses kinetic energy because no work was done on it.
It gains kinetic energy because it loses potential energy.
It loses kinetic energy because the Earth gains potential energy.
A ball rolls to the top of a frictionless hill. What is the energy transformation?
gravitational potential to kinetic
kinetic to thermal
kinetic to gravitational potential
chemical potential to kinetic
A child is at the top of a smooth slide and then slides down. At the bottom, the child comes to a stop when they reach the grass. What is the energy transformation?
elastic potential to kinetic to gravitational potential
gravitational potential to kinetic to elastic potential
kinetic to gravitational potential to kinetic
gravitational potential to kinetic to thermal
A 3.0 kg ball is on a table 1.5 m above the ground. What is its gravitational potential energy?
4.5 J
44.1 J
3.4 J
29.4 J
What is the kinetic energy of a 12 kg dog running at 3 m/s?
36 J
353 J
54 J
118 J
How much work is needed to push a resting 20 kg crate to a velocity of 5 m/s?
15 J
250 J
300 J
100 J
50 J of work is done lifting a 2.0 kg book in the air. How high was it lifted?
2.6 m
3.6 m
1.0 m
25 m
Bobby lifts a book to the second floor in 20 seconds. Carol lifts the same book to the second floor in 10 seconds. Who did more work?
Bobby
Carol
They did the same amount of work
Not enough information
A pendulum has 10 J of gravitational potential energy at its highest point. How much kinetic energy does it have at its lowest point?
0 J
2 J
5 J
10 J
At one point, a falling apple has 2 J of gravitational potential energy and 7 J of kinetic energy. How much kinetic energy does it have when it hits the ground?
2 J
7 J
9 J
5 J
A horse pulls a cart from rest to 3 m/s. Does the horse do positive or negative work on the cart?
positive
negative
not enough information
A box slides from 12 m/s to 6 m/s across a carpet. Does the carpet do positive or negative work on the box?
positive
negative
not enough information
What is the unit for energy?
joule
newton
watt
m/s/s
A man is throwing a ball off a cliff into some water below. Match the labels to where they belong on the throw's trajectory.
Max Potential Energy
Equal amounts of Potential and Kinetic
Max Kinetic Energy
An engineer is constructing a device that turns electrical energy into mechanical energy. The engineer notices that some of the electrical energy also turns into thermal energy. Which of the following describes how the device can reach maximum efficiency?
The device must minimize electrical energy while maximizing thermal
energy.
The device must minimize mechanical energy while maximizing thermal
energy.
The device must minimize thermal energy while maximizing mechanical
energy.
The device must minimize mechanical energy while maximizing electrical
energy
A new power station is being constructed, and the designers claim that it will be extremely efficient. They claim that for every 1,000,000 J of energy that is put into the station 400,000 J of energy will be produced. How efficient is the station?
40%
60%
4%
2.5%
If you apply 50 N of work to move something 2 meters, how much work did you do?
25 J
100 J
0.04 J
50 J
A 2 kg cart is released from rest from the top of a ramp that is 1 m high. Three positions of the cart are shown in the diagram. Assume friction is negligible.
Which of the following tables correctly shows the cart’s gravitational potential energy and kinetic energy at positions A, B, and C?
A student released two objects at rest, W and X, from the same height above the ground. The table shows the masses of the objects and the height from which the student dropped them.
Which of the following describes object W’s kinetic energy just before both objects hit the ground?
Object W’s kinetic energy was equal to object X’s kinetic energy.
Object W’s kinetic energy was less than object X’s kinetic energy
Object W’s kinetic energy was greater than object X’s kinetic energy.
A student released two objects at rest, W and X, from the same height above the ground. The table shows the masses of the objects and the height from which the student dropped them.
Which of the following describes object W’s velocity just before both objects hit the ground?
Object W’s velocity was one-half of object X’s velocity.
Object W’s velocity was equal to object X’s velocity.
Object W’s velocity was two times object X’s velocity.
Object W’s velocity was four times object X’s velocity.
A ball is dropped from the top of the Eiffel Tower. Describe the ball's mechanical energy as it falls.
The potential energy of the ball is conserved as it falls.
The sum of the kinetic and potential energies of the ball is a constant.
The kinetic energy of the ball is conserved as it falls.
A) The total energy of the ball increases as it falls since it gains speed.
In which of the following situations is kinetic energy decreasing?
A ball is dropped from a building.
A satellite is moving in a circular orbit around the moon.
A baseball is moving upward after being thrown up in the air.
An elevator is moving upward at a constant velocity.
The graph on the right shows the kinetic energy over time for an object in motion. At time t = 0, the potential energy of the object is 10 J. Determine the potential energy of the object at time t = 9 s.
4 J
10 J
8 J
2 J
What is the mass of an object that has 1200 J of potential energy when it is 5 meters above the ground?
10 kg
24 kg
100 kg
240 kg
If you use 30 J of energy to move an object, you have done ____ J of work.
3
10
30
0
You push a crate with a force of 100 N for 5 meters. How much work did you do?
500 J
100 J
50 J
5 J
What is the kinetic energy of a 10 kg ball moving at 3 m/s?
15 J
30 J
45 J
90 J
A 5 kg cat falls off a 3 m tall fridge. What is the cat's gravitational potential energy at the top of the fridge?
15 J
30 J
150 J
1470 J
A part of a roller coaster’s track is shown. Assume friction is negligible.
Identify where the roller coaster car has the most gravitational potential energy (GPE).
Point A
Point B
Point C
Point D
A part of a roller coaster’s track is shown. Assume friction is negligible.
Identify where the roller coaster car has the most kinetic energy (KE).
Point A
Point B
Point C
Point D
The table shows the net force that acted on an object and the distance it moved during each of four time intervals.
During which time interval was the most work performed on the object?
Time Interval 1
Time Interval 2
Time Interval 3
Time Interval 4
A student was trying to get the marble to hit the ramp. The marble was pushed off the table by the spring but went too far and missed the ramp, as shown.
Which of the following changes would result in the marble landing on the ramp?
use a heavier marble
compress the spring more tightly
use a spring that can store more energy
increase the height of the table above the ramp
Which of the following best describes what happened to the energy of the hanging object as it moved closer to the floor?
The kinetic energy of the hanging object increased as its thermal energy decreased.
The kinetic energy of the hanging object decreased as its gravitational potential energy increased.
The gravitational potential energy of the hanging object decreased as its kinetic energy increased.
The gravitational potential energy of the hanging object increased as its thermal energy increased.
