1. Kinetic Energy Objectives: Define kinetic energyp
Objectives:
Define kinetic energy
Calculate kinetic energy
Relate work and kinetic energy

2. Kinetic Energy The energy of motion

3. Formula Ek = Kinetic energy in Joules (J) m= mass in kg
v = velocity in m/s

4. Ex) A cart with a mass of 1500kg is moving at a speed of 14m/s
Ex) A cart with a mass of 1500kg is moving at a speed of 14m/s. What is the kinetic energy?

5. Ex. If a puck has 73 J of kinetic energy and a mass of 0
Ex. If a puck has 73 J of kinetic energy and a mass of 0.21kg what is its speed?

6. Ex) A 500 kg cart is moving 2m/s
Ex) A 500 kg cart is moving 2m/s. How much work must the brakes do to stop the cart?
The brakes are removing kinetic energy which is called negative work.
We assume that all the kinetic energy is removed by the brakes so that W=Ek

7. W = Ek
= ½mv2
= ½(500kg)(2m/s)2
=1x103J