1. Momentum
Mass X Velocity

2. The Principle of Conservation of Momentum
In collisions in a closed system momentum before impact equals momentum after impact.
Mass 2000Kg
Velocity ?m/s
Momentum 60000Kgm/s
Mass 1000Kg
Velocity 60m/s
Momentum 60000Kgm/s
An elastic collision

3. For collision in a closed system momentum is conserved
Mass 20Kg
Velocity 10m/s
Momentum 200Kgm/s
Mass Kg
Velocity ?m/s
Momentum 200Kgm/s
An inelastic collision

4. Momentum
The velocities of objects travelling in different directions are given different signs

5. Some examples
A car travelling at 100m/s and of mass 1600kg collides and remains attached to another car of mass 2400Kg that is parked. If they stay together after collision, what is the speed of the wreckage.

6. Answer Momentum before = Momentum after (MV)1 +(MV)2 = (M1+M2)V
1600x x0 = ( )V
= 4000V
V = 40m/s

7. Recoil
A cannon ball weighs 10Kg and the cannon has a mass of 600 Kg. If the recoil velocity of the cannon is 0.5m/s, what is the speed of the cannon ball?

8. Answer Momentum before = Momentum after (MV)1 +(MV)2 = (MV)1 - (MV)2
(10x0) + (600x0) = (10xV) – (600x0.5)
0 + 0 = 10v – 300
10V = 300
V = 30m/s

9. Newtons cradle