posted by Anonymous .
A 70.0-kg runner has a speed of 5.90 m/s at one instant during a long-distance event.What is the runner's kinetic energy at this instant? If he doubles his speed to reach the finish line, by what factor does his kinetic energy change?
1. KE=0.5mV^2=0.5 * 70 * (5.90)^2=1218J
2. 2^2 = 4 = The factor by which the KE