Question

A hockey puck of mass 0.39 kg is shot west at 2.90 m/s strikes a second puck, initially at rest, of mass 0.55 kg. As a result of the collision, the first puck is deflected at an angle of 33° south of west, with a speed of 1.45 m/s. What is the speed of the second puck after the collision?

Answer 1

Initial momentum of the first puck

Initially the second particle is at rest, It's initial momentum is zero

Total initial momentum of the system is

The final momentum of the second particle is

Let v_{​​​​​​2}​​​' be the final velocity of the second particle. The final momentum of the second particle is

Total final momentum of the system is

By the conservation of momentum

Substituting , , , we get

The speed of the second particle after the collision is