a 40-kg skater moving South at 6.2 m/s collides with a 60-kg skater moving East at 4.0 m/s. The two skaters entangle and move together across the friction-free ice. Determine the magnitude and direction of their post-collision velocity. The direction should be an angle.

Question

I know I need to set up an equation setting the initial momentum equal to the final momentum but I don't know how to set it up or what to do with the directions. Can someone help me?

Answer 1

Calculate
1. Initial momentum South m1 V1
2. Initial momentum East m2 U2

Final speed = S, final m = (m1+m2)
angle BELOW x axis = A
3. Final momentum South = (m1+m2) S cos A
4 Final momentum East = (m1+m2) S sin A

now set the initial south and east momenta = to the final ones and solve for S and A

Answer 2

whoops, reeversed sin and cos

3. Final momentum South = (m1+m2) S sin A
4 Final momentum East = (m1+m2) S cos A

Answer 3

....need more coffee!