Collision velocity?

Question

Anthony and Sissy are in a rollerskating dance championship. While 75 kg Anthony rollerskates backwards at 3.0 m/s, 60 kg Sissy jumps into his arms with a velocity of 5 m/s in the same direction.

How fast does the pair roll backwards together?

If Anthony is skating toward Sissy when she jumps, could their combined final velocity be larger or smaller than your answer to part a? Why? show calculations

Thanks in advance!

Answer 1

Hint:
m(1) * v(1) + m(2)* v(2) = m(3)*v(3)

You know
m(1) = 75kg, v(1) = 3 m/s

You should be able to figure out the result.

For part 2, just realize that Anthony's velocity will be the opposite numerical sign (-v) than Sissy.