An ice skater of mass is already sliding straight ahead on nearly friction-free ice…
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
An ice skater of mass 65kg is already sliding straight ahead on nearly friction-free ice with an initial speed of 2.0ms−1. At t=0 the skater begins to push backward on the ice so that a constant horizontal force of 94N acts on the skater in the forward direction for the next 5.0s. Assume the ice offers negligible resistance.
(a) Determine an expression for the skater’s speed as a function of time during the push.
(b) Calculate the instantaneous power being generated by the skater’s push at t=5.0s.
(c) Compute the total work done on the skater during the 5.0s interval.
(d) Using your results from parts (b) and (c), calculate the average power over the same interval and compare it to the instantaneous power at t=5.0s. Explain any difference.