A 0.50 kg ball is moving with a velocity of 8.0 m/s along a horizontal floor. It hits another ball with a mass of 0.80 kg and moving at 10.0 m/s in the opposite direction. If the first ball bounces back with a velocity of 12 m/s, with what velocity and in what direction will the second ball go after collision?



I think this is aboutĀ elastic collision so use the formula m1vi1 + m2vi2 = m1vf1 + m2vf2,
so the given in this problem is:
m1 = 0.5kg
vi1 (initial velocity 1) = 8m/sĀ 
vf1 (final velocity of 1st ball= 12 m/s
m2= 0.8kg
vi2= 10m/s
vf2 = (what you're looking for)

so just input the values on your calculator and you're done:)

also for the direction, i think it's dependent on the sign of the answer:)))))
Thank you! :)
Btw, what's your real name? :)
haha there's a reason why I didn't use it as my username. I prefer to remain anonymous:))