An arrow in a bow has 20 J of potential energy. Assuming no loss of energy to heat, how much kinetic energy will it have after it has been shot?
20 J according to the Work-Energy Theorem
100
Potential energy is the energy an object has because of its __________.
Position, height, or location
100
An object that has kinetic energy must be _________.
Moving or in motion
100
If you lift two loads up one story, how much work do you do compared to lifting just one load up one story?
Twice the work
100
How much power is required to do 30 J of work on an object in 6 seconds? (Must include units!)
5 Watts
200
Heat is the _____.
a. average amount of energy per molecule contained in an object
b. total amount of energy contained in an object
c. energy transferred between objects because of a temperature difference
d. amount of energy all the molecules have
e. all of the above
c. energy transferred between objects because of a temperature difference
200
What is the potential energy of a 1.5-kg book being held 2 m above the floor?
30 J
200
If the speed of a moving object is doubled, the kinetic energy of the object is ___________.
a. doubled
b. tripled
c. quadrupled
d. halved
c. quadrupled
200
Which requires more work: lifting a 60-kg sack vertically 2 meters or lifting a 35-kg sack vertically 4 meters?
Lifting the 35-kg sack vertically 4 meters
200
Jack and Jill have the same mass. Jack climbs the hill in 4 minutes and Jill climbs the same hill in 3 minutes. Who had more power?
Jill, she did the same amount of work in less time
300
Hot air rising above a fire would be an example of which type of heat transfer?
Convection
300
When a ball is thrown into the air, the potential energy gained must come from its kinetic energy lost. As the ball gains potential energy, its speed will __________.
decrease
300
What is the kinetic energy of a 1-kg cat flying forwards at 4 m/s? (Must include units!)
8 J
300
What is the work done in lifting 3 kg of blocks to a height of 15 m?
450 J, Remember W=Fd
300
How much power is expended if you lift a 60 N crate 10 meters in 5 second?
120 Watts
400
Energy can neither be __________ nor __________.
created nor destroyed
400
What is the potential energy of a penguin with a mass of 45 kg standing on top of a waterfall 145 m above the ground?
65,250 J
400
What is the measure of the average kinetic energy of molecules in a substance also known as?
Temperature
400
What amount of work can a 100-W motor do in 25 seconds?
2500 J of work
400
Which has the most power:
a. 60 J of work in 1 second
b. 30 J of work in 2 seconds
c. 90 J of work in 3 seconds
a. 60 J of work in 1 second
500
List three forms of energy BESIDES mechanical energy.
Answers vary but may include electromagnetic, electric, thermal, and chemical.
500
You move a 5 kg box from a shelf 1.5 m high to a shelf that is 4.2 m high. What is the change in the book’s potential energy?
It increases by 135 J.
500
A bicyclist increases her speed from 2.0 m/s to 5.0 m/s. The combined mass of the bicyclist and the bicycle is 80 kg. How much work did the bicyclist do to increase her speed?
840 J of work, W=KE
500
A toy car of mass 1.33 kg is pushed by a horizontal force of 3 N. A 1-N frictional force also acts on the car. The car travels a distance of 4.5 m. How much work is done by the force?
9 J (mass doesn't matter since the work is being done by a horizontal force)
500
A 70 kg runner is completing a stadium workout running up the entire 30 meters in 40 seconds. What is his power? (Must include units!)