Overall, 80% of the energy used by the body must be eliminated asexcess thermal energy and needs to be dissipated. The mechanisms ofelimination are radiation, evaporation of sweat (2430 kj/kg),evaporation from the lungs (38 kj/h), conduction, andconvection.
A person working out in a gym has a metabolic rate of 2500 kj/h.His body temperature is 37 degrees Celsius, and the outsidetemperature is 24 degrees Celsius. Assume the skin has an area of2.0 m^2 and emissivity of 0.97. (a) At what rate is his excessthermal energy dissipated by radiation? (b) If he eliminates 0.4 kgof perspiration during that hour, at what rate is thermal energydissipated by evaporation of sweat? (c) At what rate is energyeliminated by evaporation from the lungs? (d) At what rate must theexcess remaining excess energy be eliminated though conduction andconvection?
Overall, 80% of the energy used by the body must be eliminated asexcess thermal energy and needs to be dissipated. The mechanisms ofelimination are radiation, evaporation of sweat (2430 kj/kg),evaporation from the lungs (38 kj/h), conduction, andconvection.
A person working out in a gym has a metabolic rate of 2500 kj/h.His body temperature is 37 degrees Celsius, and the outsidetemperature is 24 degrees Celsius. Assume the skin has an area of2.0 m^2 and emissivity of 0.97. (a) At what rate is his excessthermal energy dissipated by radiation? (b) If he eliminates 0.4 kgof perspiration during that hour, at what rate is thermal energydissipated by evaporation of sweat? (c) At what rate is energyeliminated by evaporation from the lungs? (d) At what rate must theexcess remaining excess energy be eliminated though conduction andconvection?
