By jogging, a girl is converting food energy into internal energy at the rate of 399 kcal/h above her basal metabolic rate (BMR). Some of this additional internal energy immediately goes into work done at a rate of 56.1 W. The rest of this additional energy would go into raising her temperature, but it is instead eliminated by evaporation of perspiration to keep her body temperature constant. Assume that the heat of evaporation of water at body temperature is equal to its heat of vaporization at 100ºC. (a) Determine the hourly rate (in kg/h) at which water must evaporate from her skin. kg/h (b) When fat is metabolized, hydrogen atoms in fat molecules are transferred to oxygen to form water. Assume that the metabolism of 1.00 g of fat generates 9.00 kcal of energy and produces 1.00 g of water. What percent the water needed is generated by burning fat? %

By jogging, a girl is converting food energy into internal energy at the rate of 399 kcal/h above her basal metabolic rate (BMR). Some of this additional internal energy immediately goes into work done at a rate of 56.1 W. The rest of this additional energy would go into raising her temperature, but it is instead eliminated by evaporation of perspiration to keep her body temperature constant. Assume that the heat of evaporation of water at body temperature is equal to its heat of vaporization at 100ºC. (a) Determine the hourly rate (in kg/h) at which water must evaporate from her skin. kg/h (b) When fat is metabolized, hydrogen atoms in fat molecules are transferred to oxygen to form water. Assume that the metabolism of 1.00 g of fat generates 9.00 kcal of energy and produces 1.00 g of water. What percent the water needed is generated by burning fat? %

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter17: Energy In Thermal Processes: The First Law Of Thermodynamics

Section: Chapter Questions

Problem 60P

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