Question

A 60.0 kg runner expends 355 W of power while running a marathon. Assuming that 8.00% of the energy is delivered to the muscle tissue and that the excess energy is primarily removed from the body by sweating, determine the volume of bodily fluid (assume it is water) lost per hour. (At 37.0°C the latent heat of vaporization of water is 2.41 106 J/kg.)


I don't know what to do with this...

Answer 1

92% of the 355 W becomes body heat. That equals 327 W. In one hour, that is a total heat energy of 3600*327 = 1.18*10^6 J. Divide that by the latent heat of vaporization for the # of kg of sweat evaporated