Question

A 1300-kg car moving north at 27.0 m/s is struck by a 2165-kg car moving east at 17.0 m/s. The cars are stuck together. How fast and in what direction do they move immediately after the collision?

Answer 1

Write two equations of conservation of momentum

m1u1 + m1u2 = m1v1 + m2v2

One in the i direction (West to East)
One in the j direction (South to North)

v1 = v2 in both cases (i and j) because they stick together afterwards.

For example:

Velocity of the 1300kg car is 0i + 27j and
the velocity of the 2165kg car is 17i + 0j

So, find i afterwards (call it x) and j afterwards (call it y) and the velocity afterwards of the combined cars is xi + yj. You can find the velocity and angle from that then.

Answer 2

edit: m1u1 + m2u2 = m1v1 + m2v2
I had a small error in the previous post with that formula.