Question

Which is the momentum of a 100 kilogram boulder rolling south down a hill at a velocity of 5 meters per second?


20 kilogram meters per second south

500 kilogram meters per second north

500 kilogram meters per second south

Answer 1

The momentum of an object is the product of its mass and velocity. The direction of the velocity here is south, so already you can eliminate the second choice because momentum needs to be in the same direction.

The magnitude of the momentum is 5 x 100 = 500 kg m/s, meaning the third choice is your answer!