WEBVTT

1
00:00:00.000 --> 00:00:05.828
Here is the problem: What is the momentum of a 70 kg object moving at 9 m/s?

2
00:00:06.278 --> 00:00:10.980
Use the momentum formula, rearranged for the unknown, in SI units.

3
00:00:11.780 --> 00:00:13.034
Formula: momentum.

4
00:00:13.484 --> 00:00:15.388
Substitute the known values.

5
00:00:16.188 --> 00:00:21.923
So the answer is momentum p equals 630 kg times m/s.

6
00:00:22.373 --> 00:00:37.269
Momentum is a vector with the same direction as the velocity; in one dimension the sign shows the direction. A 1000 kg car at 20 m/s and a 10 kg ball at 2000 m/s carry the same momentum.

7
00:00:38.069 --> 00:00:43.793
Substituted every value back into the formula: both sides agree, which checks out.