# Newtons Third Law and Momentum Newtons Third Law

• Slides: 9

Newton’s Third Law and Momentum

Newton’s Third Law For every action there is an equal and opposite reaction. That means if I push on the wall pushes back on me with the same amount of force.

What is Momentum is how hard something is too stop. An objects mass and it’s velocity determine it’s momentum.

Momentum The larger and objects mass the harder it is to slow down. The faster and object goes the harder it is to slow down.

Momentum The formula to calculate momentum is: Mass x Velocity Momentum is represented by a symbol: p The unites for momentum are: kg x (m/s)

Conserving Momentum can be transferred from one object to another. In fact momentum is always conserved. This is called: The Law of Conservation of Momentum.

Conserving Momentum To conserve momentum one object smacks another object and part of the force is applied to the second object. For this to happen it must be in a closed system. Closed system means no other forces are involved.

Example A train car is sitting on the tracks, another train car comes rolling up behind it and smacks in to the first. What happens? The second car goes flying with the same momentum as the first and the first stops.

Calculating Momentum If a bullet has a mass of 10 g and is traveling at 5 m/s what is the momentum? p = mass x velocity p = 10 x 5 p = 50 g(m/s)