# A Billiard Ball Moving With A Speed Of 5M/S Collides With An Identical Ball Originally At Rest. If The First Ball Stops After Collision, Then The Second Ball Will Move Forward With A Speed

Since There is no external force, we can apply momentum conservation,

$$P_{1} = m(V) = 5m$$ $$P_{2} = 0$$ $$P_{i} = 5m + 0 = 5m$$ $$P_{f} = m * 0 + mv_{2}$$ $$P_{i} = P_{f}$$ $$5m = mv_{2}$$ $$v_{2} = 5m/s$$

Due to the elastic collision of bodies having equal mass, their velocities get interchanged.

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