1. Review for test on
Energy

4. on e

5. An object with a mass of 20 kg is moving
5 m/s. What is its kinetic energy?
5 x 5 = 25 (velocity squared)
25 x 20 = 500 (mass x velocity)
500 / 2 = 250 j

7. 3 types of potential energy:
Gravitational
Elastic
Chemical
All energy is measured in Joules

8. GPE = weight (N) x height (m)
Weight = mass (kg) x gravity (9.8 N)
GPE can also be stated as mgh
A lift raises a 500 kg car 5 m off the ground.
What is the potential energy given to the
car?
500 kg x 9.8 N = 4,940 (N) x 5 = 24,700 j

9. Potential energy is Not
Lost…it’s converted to KE

14. Seven forms of energy:
MRS CHEN
Mechanical – Sum of PE + KE
Radiant – Light
Sound
Chemical – batteries, food
Heat – Thermal
Electrical
Nuclear – happens in nucleus of atoms: Fission – man made; Fusion - sun

15. What is the difference between Heat and
Temperature?
Heat is the total energy of molecular
motion in a substance while
temperature is a measure of the average energy
of molecular motion in a substance.

16. Floor heater

17. What is work?
What is power?
Work: using a force to move an object a distance. To do work, an object must move in the direction a force is applied.
Power is how quickly work is done; it is the rate, or speed, at which energy is transferred.

18. SI unit is in joules
SI unit is in watts

19. Pre-AP only:
A lady ran for 3,000 seconds and her energy
output is 270,000 joules. What was her
average power?
Power = work (J) / time (s)
270,000 / 3,000 = 90 watts

20. Initial PE changes to Electrical energy
Know the difference between a renewable
resource and a non-renewable resource.