1. The problem statement, all variables and given/known data Man with a temperature of 310.15 K and a mass of 70 kg drinks 0.4536 kg of water at 275 K. Ignoring the temperature change of the man from the water intake (assume human body is a reservoir always at same temperature), find entropy increase of entire system. 2. Relevant equations dS = - absvalue(Q)/Tbody deltaS = mcln(Tfinal/Tinitial) 3. The attempt at a solution I'd tried solving only using the second equation on here, but the answer only used that equation for the deltaS of the water. The natural log of the body would be 0, since T is constant, so I thought there wouldn't be an enthalpy change for the body. I don't understand under what circumstances the first equation would be used instead of the second equation. Also, the numbers plugged into the first equation for the deltaS(body) are -m(water)(1) [(Tbody-Twater)/Tbody] which is nothing like what the first equation asks for, so I am very confused.