Posted by Anonymous on .
A 120kg tackler moving at 5 m/s meets headon (and tackles) a 80kg halfback moving at 5 m/s, after which they couple together.
What will be their mutual speed after the collision?
Hint: use conservation of momentum law for INELASTIC collision.

physics 
Dan B,
Mass1(tackler) x V1(tackler) + M2(halfback) x V2(halfback) = (M1 + M2) x V(combined)
or
m1(v1) x m2(v2) = (m1+m2)v
=== solve for v ====
(remember, they are running in opposite directions, one velocity should be in the negative direction)