While running, a person dissipates about 0.554 J of mechanical energy per step per kilogram of body mass. If a 62.5 kg runner dissipates a power of 65.4 W during a race, how fast is the person running? Assume a running step is 1.50 m in length. Well I know that the person loses 34.6 J of mech energy every 1.5 m and loses a total of 65.4 watts during the entire race. Now 65.4 W is just 65.4 J/s, so how can I further relate all of these givens? I am a little confused. Thanks for any help in advance.