The 200 m free style women’s swimming gold medal at Seol Olympic 1988 went to Heike Friendrich of East Germany when she set a new Olympic record of 1 minute and 57.56 seconds. Assume that she covered most of the distance with a uniform speed and had to exert 460 W to maintain her speed. Calculate the average force of resistance offered by the water during the swim.
Distance covered, d= 200 m
Time in which she covered the 200m distance, t = 1minute 57.56 seconds = 117.56 seconds
Power exerted in this time period = 460 W or J/s
Work done in covering this distance with given conditions, W = Power × Time
= 460 × 117.56
= 54077.6 J
Also, this work done W = Force × distance covered
Magnitude of this force of resistance = W/d
= 54077.6/200
= 270.388 N
≈ 270 N