The athlete Emily Davis won the 100 m sprint gold medal at London Olympic 2012 setting a new Olympic record of 10.54 s . Assume that she achieved her maximum speed in a very short time and subsequently ran the race with that speed till she crossed the line. Take her mass to be 50 kg . Calculate the kinetic energy of Emily Davis at her full speed.

Step-by-step solution

Given that the athlete achieved her maximum speed in a very short time and maintained it throughout the race, her speed can be considered constant. The constant speed is given by: v = Distance Time = 100 10.54 9.487 m/s The kinetic energy K of the athlete at her full speed is: K = 1 2 mv^2 Substituting the given values ( m = 50 kg ): K = 1 2 50 ( 100 10.54 )^2 K = 25 90.015 2250 J