1. Day 2:

2. What is energy?
Energy measures the ability for things to change themselves or to cause change in other things. It is measured in Joules.
Some examples are changes in temperature, speed, position, pressure, or any other physical variable.

3. kinetic Energy Energy of motion is called kinetic energy.
A moving cart has kinetic energy because it can hit another object (like clay) and cause change.

4. Kinetic Energy KE = ½ mv2 KE (joules) mass of object (kg)
velocity (m/sec)

5. KE = ½ mv2 KE = (5 kg) (5 m/s)2 (½ ) (5) (25) (½ ) KE = KE =
The bird has a mass of 5 kg. It is flying at a speed of 5 m/s. Find its KE.
Do the square first! PEMDAS!
KE = ½ mv2
KE =
(5 kg)
(5 m/s)2
(½ )
(5)
(25)
(½ )
KE =
KE =
62.5 Joules (J)

6. Potential energy
Systems or objects with potential energy are able to exert forces (exchange energy) as they change.
Potential energy is energy due to position.

7. Why is tigger moving?
Elastic Potential Energy: energy stored when you stretch a rubberband or push down a spring

8. Why is the elephant moving?
Gravitational Potential Energy: just by lifting something up, you give it energy.

9. What happens to the pumpkin?
Chemical Potential Energy: putting together chemicals that will cause a chemical reaction

10. Potential Energy PE = mgh mass of object (g) height object raised (m)
PE (joules)
height object raised (m)
PE = mgh
gravity (9.8 m/sec2)

11. PE = mgh PE = (2 kg) (9.8 m/s2) (10 m) PE = 196 Joules (J)
If your egg drop device has a mass of 2 kg, how much potential energy does it hold at a height of 10 meters?
G = 9.8 m/s2
PE = mgh
PE =
(2 kg)
(9.8 m/s2)
(10 m)
PE =
196 Joules (J)