Question

While goofing off at the ice skating rink, a student takes off her shoes and places each of them on the ice. Her friend, a hockey player, then shoots a hockey puck at each shoe. The first puck immediately comes to rest after it collides with the left shoe. The second puck rebounds after it collides with the right shoe. If each hockey puck has the same incoming speed, which shoe has greater speed after the collision?
A. left shoe

B. right shoe

C. both are the same

Answer 1

Answer:

B. right shoe

Explanation:

When the puck comes to a stop after it collides with the left shoe both their velocities becomes zero. This means that their relative velocities is zero as the linear momentum is conserved.

When the puck rebounds after it collides with the right shoe then the right shoe will also move as linear momentum is conserved.

For elastic collision

$m_{1}u_{1}+m_{2}u_{2}\ =m_{1}v_{1}+m_{2}v_{2}$

Hence, the right shoe will have a greater speed after collision.