High School

In a little sticks hockey game at the community ice rink, a 0.105 kg hockey puck moving at 27.6 m/s is caught and held by a 35.9 kg goalie who is at rest. With what speed (in cm/s) does the goalie slide on the ice after the catch?

Answer :

Final answer:

Using the conservation of momentum principle, the goalie slides on the ice at a speed of 8.03 cm/s after catching the hockey puck.

Explanation:

To find the speed with which the goalie slides on the ice after the catch, we can use the principle of conservation of momentum. Since there are no external forces acting on the system horizontally, the total momentum before the catch equals the total momentum after the catch.

The formula for momentum is momentum = mass × velocity. Before the catch, the momentum is only that of the puck since the goalie is at rest. After the catch, the system's momentum is the combined mass of the goalie and the puck moving with the new velocity. Setting the initial and final momenta equal to each other:

× 0.105 kg × 27.6 m/s = (0.105 kg + 35.9 kg) × v_final

Solving for v_final, we get:

v_final = (0.105 kg × 27.6 m/s) / (0.105 kg + 35.9 kg)

v_final = 0.0803 m/s

To convert this to cm/s, we multiply by 100 (since 1 m = 100 cm), giving us 8.03 cm/s. Therefore, the goalie slides on the ice at a speed of 8.03 cm/s after the catch.