39. IE •• Evaporation of water from our skin is an important mechanism for controlling body temperature.

(a) This is because (1) water has a high specific heat,

(2) water has a high heat of vaporization, (3) water contains more heat when hot, (4) water is a good thermal conductor.

(b) In a 3.5-h intense cycling race, a cyclist can lose 7.0 kg of water through perspiration.

Estimate how much internal energy the cyclist loses in the process.