Download Work, Energy, Power, Simple Machine Review Sheet

Work, Energy, Power &
Simple Machine Review Sheet
Name ______________________
1. What is the equation for work? What is the unit? What are the two requirements necessary for work to
be done?
2. Is energy ever created or destroyed? What is this called?
3. What happens to the total amount of energy of a system? What must be done to transfer mechanical
energy?
4. What happens to the work if the force is increased? The distance increased? So if an object is pushed
three times the distance with three times the force what happens to the work?
5. What is happening to the speed of an object if the net work on the object is positive?
6. What are the two types of mechanical energy? What is the difference between them?
7. If an object is sitting on a table, what type of energy does it have? What happens to the energy if the
object falls off the table?
8. How can potential energy be increased? Decreased?
9. What happens to the kinetic energy of an object if both the mass and the velocity of the object are
increased?
10. By how much will the kinetic energy change if the mass is doubled and the velocity is doubled?
11. Why do we use simple machines? Do they increase our energy?
12. What is the ratio of work out to work in?
Work, Energy, Power &
Simple Machine Review Sheet
Name ______________________
Calculations
1.
A 0.2 kg pie sitting on the windowsill falls 3 m. Just before hitting the ground, what will be its kinetic
energy?
2.
What is the power expended in lifting 25 N 6 m in 2 seconds?
3.
A 65 kg student carrying an 8 kg backpack climbs a flight of stairs 5 m high. What is the student’s
potential energy?
4.
What is the kinetic energy of a 25 kg tricycle that is moving at 2 m/s?
5.
An apple pie weighing 1.2 N us sitting on a windowsill 12 meters above the ground. What is the pie’s
potential energy?
6.
During a certain time interval, a 15 N object falls 12 m. What is the potential energy? How much
kinetic energy does the object gain during this time?
7.
How much power must a motor have to operate a pump that raises 1150 kg of water 12 m every minute?
8.
The above box has a mass of 15 kg. It was pushed up a ramp to a height of 4 meters above
the ground. Determine:
a) the work needed to reach the top of the ramp
b) Total Energy (TE)
c) PE and KE values in the diagram on your answer sheet