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BIO Basal Metabolic Rate. The basal metabolic rate is the
Chapter 17, Problem 116P(choose chapter or problem)
BIO Basal Metabolic Rate. The ?basal metabolic rate is the rate at which energy is produced in the body when a person is at rest. A 75-kg (165-lb) person of height 1.83 m (6 ft) has a body surface area of approximately 2.0 m2. (a) What is the net amount of heat this person could radiate per second into a room at 18°C (about 65°F) if his skin’s surface temperature is 30°C? (At such temperatures, nearly all the heat is infrared radiation, for which the body’s emissivity is 1.0, regardless of the amount of pigment.) (b) Normally, 80% of the energy produced by metabolism goes into heat, while the rest goes into things like pumping blood and repairing cells. Also normally, a person at rest can get rid of this excess heat just through radiation. Use your answer to part (a) to find this person’s basal metabolic rate.
Questions & Answers
QUESTION:
BIO Basal Metabolic Rate. The ?basal metabolic rate is the rate at which energy is produced in the body when a person is at rest. A 75-kg (165-lb) person of height 1.83 m (6 ft) has a body surface area of approximately 2.0 m2. (a) What is the net amount of heat this person could radiate per second into a room at 18°C (about 65°F) if his skin’s surface temperature is 30°C? (At such temperatures, nearly all the heat is infrared radiation, for which the body’s emissivity is 1.0, regardless of the amount of pigment.) (b) Normally, 80% of the energy produced by metabolism goes into heat, while the rest goes into things like pumping blood and repairing cells. Also normally, a person at rest can get rid of this excess heat just through radiation. Use your answer to part (a) to find this person’s basal metabolic rate.
ANSWER:Solution 116P Step 1 The rate of heat radiation is given by dQ 4 4 dt = A(T 1 T 2 ) From the given problem we know that = 1.0 8 2 4 = 5.67 × 10 W/m K 2 A = 2.0 m T 1 30°C = 303 K T = 18°C = 291 K 2 dQ = (1.0)(5.67 × 108 W/m K )(2.0 m )[(303 K) (291 K) ] = 142.6 W dt So the person can radiate 142.6 J of heat per second.