During a dry day, a 70.0 kg athlete runs a marathon while the outside temperature is T2 = 33.2 ¢XC. The thermal power produced by the athlete's body is P = 1.05 ¡Ñ 103 W and the skin temperature is T3 = 35.5 ¢XC so that the themal exchange due to convection, radiation and conduction are negligible.

Question

During a dry day, a 70.0 kg athlete runs a marathon while the outside temperature is T2 = 33.2 ¢XC. The thermal power produced by the athlete's body is P = 1.05 ¡Ñ 103 W and the skin temperature is T3 = 35.5 ¢XC so that the themal exchange due to convection, radiation and conduction are negligible.  
a) What quantity of sweat must be evaporated per second so that the athlete's body temperature will remain constant. 
   
b) The maximum sweat production rate is Ds = 0.220 g s−1. What is the thermal energy increase of the athlete's body per second? 
 
c) How long would it take to increase the body temperature by 1.00 ¢XC if there is no other mechanism of heat loss other than evaporation? The specific heat of the athlete's body is 4.50 ¡Ñ 103 J kg−1 K−1