Physics problem help --- momentum problem help?

Question

A 1700 kg car traveling north (+j hat ) at 70 km/h collides at an intersection with a 2000 kg car traveling west (-i hat) at 41 km/h. The two cars stick together.

(a) What is the total momentum of the system before the collision?

( _____ i hat + _____ j hat ) kg·km/h

(b) Find the magnitude and direction of the velocity of the wreckage just after the collision.

______km/h

______° (west of north)

Answer 1

here are the two main ideas which you need for this question:

1) momentum = mass x velocity (speed)

2) momentum before a collision is equal to the momentum after a collision

try to have a go for yourself as you'll remember it better that way