Before colliding, the momentum of Block A is +450 kg*m/s, and Block B is -150 kg*m/s. After, Block A has a momentum +100 kg*m/s. What is the momentum of Block B afterwards?

Answer 1

The total momentum is conserved. The total momentum "before" is 450 - 150 = 300 kg•m/s so the total momentum "after" must also equal 300 kg•m/s. So "momentum after - block A" + "momentum after - block B" = 300 or:

"momentum after - block B" = 300 - "momentum after - block A"

"momentum after - block B" = 300 - 100

"momentum after - block B" = 200 kg•m/s