In exercising, a weight lifter loses 0.236 kg of water through evaporation, the heat required to evaporate the water coming from the weight lifter's body. The work done in lifting weights is 1.41 x 105 J. (a) Assuming that the latent heat of vaporization of perspiration is 2.42 x 106 J/kg, find the change in the internal energy of the weight lifter. (b) Determine the minimum number of nutritional Calories of food that must be consumed to replace the loss of internal energy. (1 nutritional Calorie = 4186 J).
I got (a) right with the answer of -712120 J. But I'm stuck on part b)
I just divide Q = (0.236)*(2.42x10^6) = 571,120 by 4186 and i get = 571120/4186 = 136.44, but this answer is wrong. Any ideas please ?
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