A hockey puck of mass 0.17 kg is struck on a nearly friction-free horizontal ice rink
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A hockey puck of mass 0.17 kg is struck on a nearly friction-free horizontal ice rink. Immediately after the strike the puck is observed to be sliding eastward at 8.0 m/s. A thin patch of rough ice, 3.0 m wide, lies 20 m directly in the puck’s path. Beyond the patch the ice again behaves as friction-free for a long distance.
Respond to the following, using clear, well-organized, and physics-based reasoning.
(a) Describe the motion (speed and direction) of the puck during the first 20 m of travel before it reaches the rough patch. Include an explanation based on appropriate physical principles.
(b) While crossing the rough patch the puck experiences a constant kinetic friction force of magnitude 0.25 N opposite its motion. Determine the puck’s speed as it leaves the rough patch.
(c) After the puck exits the rough patch, describe its subsequent motion. Explain how your answer is consistent with the concept of an inertial reference frame.