The latent heat of vaporization of sweat is 2 430 kJ/kg at body temperature.Assuming that sweating is the only mechanism for dissipating heat,what would be the maximum sustainable metabolic rate if 75% of the energy used by the body goes into waste heat? The body can produce up to 1.5 kg of sweat per hour.

Question

The latent heat of vaporization of sweat is 2 430 kJ/kg at body temperature.Assuming that sweating is the only mechanism for dissipating heat,what would be the maximum sustainable metabolic rate if 75% of the energy used by the body goes into waste heat? The body can produce up to 1.5 kg of sweat per hour.​

Quizplus · Accepted Answer

The maximum sustainable metabolic rate can be calculated as follows:

Energy used by the body = Energy dissipated as waste heat + Energy used for metabolic processes

Let's assume the energy used for metabolic processes is X.

The energy dissipated as waste heat will be 75% of X = 0.75X

The energy used by the body to produce 1 kg of sweat is 2 430 kJ/kg

Therefore, the energy used by the body to produce 1.5 kg of sweat per hour is:

2 430 kJ/kg x 1.5 kg/hour = 3 645 kJ/hour

This energy must be equal to the energy dissipated as waste heat:

3 645 kJ/hour = 0.75X

X = 4 860 kJ/hour

Finally, we convert this to watts:

4 860 kJ/hour = 1.35 kW

Answer: D) 1.4E+3 W

The Latent Heat of Vaporization of Sweat Is 2 430