A ball with a mass of 9kg moving at 15ms hits a still ball with a mass of 2kg. If the first ball stops moving, how fast is the second ball moving? Physics Momentum and Collisions Conservation of Momentum 1 Answer ali ergin Feb 10, 2016 v=67,5ms Explanation: ∑Pb=∑Pa sum of momentums before event ,must be equal sum of momentums after event 9⋅15+0=0+2⋅v 135=2⋅v v=1352 v=67,5ms Answer link Related questions Why does Newton's cradle stop? How does the conservation of momentum apply in rotational motion? How does the conservation of angular momentum effect the stability of a bike? What is the law of conservation of momentum? What is conservation of angular momentum? What is an inelastic collision? What are some examples of an elastic collision? What is an elastic collision? What is the conservation of momentum? A fly splats on your windshield. What is the collision type? See all questions in Conservation of Momentum Impact of this question 1591 views around the world You can reuse this answer Creative Commons License