4.11 Momentum (Part 1)

Question 1

What is the law of conservation of momentum?

Answer 1

In a collision when no other external forces act, momentum is conserved - i.e. the total momentum after a collision is the same as it was before it

Question 2

How does a gun firing a bullet have the same momentum before and after?

Answer 2

It’s initial momentum before is 0 as it’s velocity is 0 however once the gun fires, the bullet that fires out will have a momentum in the forward direction and so to compensate for this the gun has the recoil backwards with an equal momentum so that together the total momentum is still 0.

Question 3

Momentum is a ________ quantity

Answer 3

vector

Question 4

The units for momentum are:

Answer 4

kg m/s