1. Think Pair Share
As the girl swings back and forth, describe her potential energy and kinetic energy at A, B, and C. A C B

2. Calculating Energy!

3. Calculating Kinetic Energy
The energy of motion
Formula:
KE = ½ x mass x (velocity)2
First:
Square the velocity
Second:
Multiply the three numbers together

4. Units of Energy
Joule
1 Joule = 1 N•m
1 Joule = 1 km • m2/s2

5. Calculating Gravitational Potential Energy
An objects stored energy as the result of its position.
Formula:
GPE = mass x gravity x height
Force due to Gravity:
9.8 m/s2

6. Practice
Determine the kinetic energy of a 625-kg roller coaster car that is moving with a speed of m/s.

7. Practice
Which has more kinetic energy: a 100 kg person going 7 m/s or a 10 kg monkey going 15 m/s?

8. If you wanted to increase the GPE of an object, name 2 things that you could do?

9. Practice
A brick is placed on top of a cart. If the mass of a brick is 3.0 kg and the height of the cart is meters, then what is the gravitational potential energy of the brick?

10. Practice
A person has a mass of 60 kg and is standing on a ladder at a height of 3 km. What is the person’s potential energy?

11. Mechanical Energy
The total amount of kinetic and potential energy in a system
ME = PE + KE

12. Practice
A girl is swinging on a swing set. At one point while she is swinging, her PE is 40 Joules and her KE is 2 Joules. Determine the Mechanical Energy of the system.

13. Practice Rocket mass: 5 kg Rocket speed: 20 m/s Height: 50 meters
What is the rockets:
Potential energy?
Kinetic energy?
Mechanical energy?