Question

Ball 1, with a mass of 10kg, is moving to the right at 20 m/s. Ball 2 is moving to the left at 20 m/s. Upon collision, ball 2 comes to a standstill, and ball 1 moves to the left at twice its origional speed. What is the mass of ball 2? .

Answer 1

For us to know the mass of ball 2, we will be using the law of momentum conservation which is the momentum before collision and the momentum after collision (m1v1+m2v2=m1v1+m2v2):

(10×20) + (m×−20) = (10×−40) + (m×0)

200 − 20m = −400

Since we are looking for “m” which is the mass of ball 2, derivation will be needed.
Then:

m = (−400−200) / (−20) = 30kg

Therefore, it is concluded that the mas for ball 2 is 30kg.