momentum q?

Question

a 95 kg fullback, running at 8.2 m/s, collides in midair with a 128 kg defensive tackle moving the opposite direction. both players end up with zero speed.

[a] what is the change in the fullback's momentum?
[b] what is the change in the tackle's momentum?
[c] what was the tackle's original momentum?
[d] how fast was the tackle moving originally?


please show steps. @__@

exclude a, i figured it out !!

Answer 1

Let m=mass of fullback = 95kg
v = speed of fullback = 8.2 m/s
M=mass of defensive tackle = 128 kg
V= speed of defensive tackle

mv + MV = 0

a) momentum of fullback to start is mv; at end it is 0; the change of momentum is mv;
b) change in tackle's momentum is MV = -mv
c) tackle's original momentum is MV = -mv
d) V = -mv/ M