A hockey puck on a frictionless horizontal surface is simultaneously subject to a…
PHYSICS · Multi-part · CBSE · Physics · Work, Energy and Power · Work, Energy and Power
Problem
A hockey puck on a frictionless horizontal surface is simultaneously subject to a constant force F=(20N)^+(15N)^. At a particular instant the puck’s velocity is v=(3.0ms−1)^−(2.0ms−1)^.
(a) Determine the instantaneous rate at which the force is transferring energy to the puck at that instant.
(b) Calculate the angle between the force and velocity vectors at that instant and state whether the force is doing positive work, negative work, or no work on the puck. Justify your answer mathematically and verbally.
(c) If the puck’s velocity were reversed in direction but kept the same magnitude, describe qualitatively and, if possible, quantitatively how the instantaneous rate of energy transfer would change.