Collision

[jazzchan]

I have a problem as follows:

A rugby player, mass 120 kg is running due south at 6 m/s. He is tacked by an opponent, mass 90 kg, due east at 8 m/s. Calculate the combined speed of the joined players immediately after the tacke.

I assume that

m1*u1 + m2*u2 = (m1+m2)V

is it right ?

thanks

jazz

[arildno]

True enough, but remember:
1.There's no way but to treat the velocities as vectors here!
2. You are asked for the SPEED, rather than the VELOCITY, so your final answer should be a scalar(number), not a vector