1. Linear Momentum
AP Physics

2. Momentum
Momentum = mass x velocity
Momentum = p
Unit = kg m/s
p=mv

3. Momentum
2 cars have the same mass – one is moving fast, the other slow. The fast car has more momentum than the slow car.
2 cars moving at same speed – the heavier car will have more momentum than the lighter car.

4. Momentum and Force
F = ∆p ÷ ∆t
∆p is called Impulse
∆p= Fnet ∆t

5. Law of Conservation of Momentum
The total momentum of an isolated system remains constant during a collision.
momentum before = momentum after
∆p = 0
Isolated system – no outside forces present

6. Equations for Momentum
1 car moving : mv 2 cars moving separately : m1v1 + m2v2 2 cars stuck together moving : v(m1 + m2)

7. Collisions Elastic collision – the objects bounce off each other.
Kinetic energy is conserved
Inelastic collision – the objects stick together.
Kinetic energy is not conserved
Partially inelastic (deformed but not stuck)
Totally inelastic (stuck together)

8. 2D Collisions
If a collision occurs in 2 dimensions, momentum is still conserved.
You will have
∆px=0
∆py=0

9. Examples
Write ALL of these examples down. There are lots of them.