Download XUnit 7 8 4Work Energy Power Add Review

Name: ______________________________
Period: _______________
Energy, Work, and Power Review
Formulas:
G.P.E.= mgh
K.E. = ½ mv2
P= W/t
Gravity= 9.8 m/s2
W= Fd
1.) An object has gravitational potential energy based on its location. If an object is
sitting on the ground, how much gravitational potential energy does it have?
2.) When does a ball rolling down a hill have the most kinetic energy?
3.) If you find that twice as much work is needed to perform a task but it takes twice as
much time, what happens to the power needed to perform the task?
4.) Using 500 J of work, a toy elevator is raised from the ground floor to the second floor
in 10 seconds. The power needed to do this job is?
5.) What is the law of conservation of energy?
6.) In order to have kinetic energy what must an object be doing?
7.) Two identical jobs are performed, one slowly and one quickly. Which one requires
more work? Which one requires more power?
8.) A man pushes a crate 20 meters across a floor with a force of 4 Newtons. How much
work has he done?
9.) What unit is work measured in?
10.) What unit is power measured in?
11.) What is the scientific definition of work?
Name: ______________________________
Period: _______________
12.) An object has a mass of 5 kg and velocity of 2 m/s. What is this objects kinetic
energy?
13.) When we watched the video about the car commercial, was any energy created or
destroyed? Why or why not?
14.) If I carry a 15 kg rock across a desert for 5 hours. How much work have I done?
15.) A roller coaster cart that weighs 50 kg is elevated 100 meters off the ground. What
is this roller coaster cart’s potential energy?
16.) When an automobile is braked to a stop, what is its kinetic energy converted to?
17.) A battery converts chemical energy to __________________ energy
18.) Of the 7 forms of energy, which one has the most amount of energy in the smallest
amount of space?
19.) Work or not? Michael Jordan shoots a three pointer
20.) Why can no machine every have 100% efficiency?
21.) The work-energy theorem tells us that if more work is done on an object than that
objects ___________________ energy increases
22.) If I have an input force of 2 Newtons and an output force of 40 Newtons. What is
my mechanical advantage?