# Physics - Momentum

## See also:

[[Physics - Collisions in 2D]]^{A}

What is the symbol symbol formula for momentum?

What is the word formula for momentum?

What are the units for momentum?

Two cars, $A$ and $B$ are travelling in the same direction at $30mph$ and $31mph$ respectively. What could be said about the “magnitude” of the collision?

It’s the same as a $1mph$ collision.

Two cars, $A$ and $B$ are travelling towards each other at $30mph$ and $31mph$ respectively. What could be said about the “magnitude” of the collision?

It’s a $61mph$ collision.

What is the Principle of the Conservation of Momentum?

The total momentum of two objects before a collision is equal to the total momentum of the two objects after a collision.

What is the height of the Burj Khalifa?

How much does The Rock weigh, in kilograms?

How can the total momentum before and after an explosion be the same?

Momentum is a vector, each individual piece of shrapnel has a momentum that sums to zero.

What is the momentum of a watermelon resting on a table?

What is the momentum of an exploding watermelon?

For an elastic collision, what is true about momentum?

It is conserved.

For an elastic collision, what is true about total energy?

It is conserved.

For an elastic collision, what is true about kinetic energy?

It is conserved.

For an inelastic collision, what is true about momentum?

It is conserved.

For an inelastic collision, what is true about total energy?

It is conserved, but transferred.

For an inelastic collision, what is true about kinetic energy?

It is **not** conserved.

### 2021-01-21

How should you actually define the Law of Conservation of Momentum?

In a closed system, linear momentum is conserved in both directions.