After the collision, both balls continue moving in the same, original direction, and the speed of the 0.099 kg ball is 0.26 m/s.
What is the new velocity of the first ball? (in m/s in the original direction)© BrainMass Inc. brainmass.com September 19, 2018, 4:56 am ad1c9bdddf - https://brainmass.com/physics/conservation-of-momentum/collision-between-plastic-balls-161362
Apply the conservation of momentum to solve the question.
before the collision, the total momentum of the two balls is
It shows how to find the speed of the ball after it collides with another plastic ball. The solution is detailed and has a '5/5' rating.