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A 50.0-kg student evaluates a weight loss program by calculating the number of times she would need to climb a 12.0-m high flight of steps in order to lose one pound (0.45 kg) of fat.
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- After eating a 200 g pottle of yoghurt, a person decides to go for a run to burn off the extra energy. The yoghurt provides 5.4 MJ kg−1, and he is able to raise his metabolic rate to 220W while running. How long does he have to run?arrow_forwardWhen someone has a fever, his or her body temperature might increase by as much as 2°C. Suppose this person has a mass of 48 kg. (a) About how much energy is required to raise a person’s temperature this much? The energy required to raise the person’s temperature is ___J (b) What is this energy in food calories? (1 food calorie ≡ 1 Cal ≡ 1000 calories = 1 kcal.) The energy in food calories is ___calarrow_forwardA 4-ton air conditioner removes 5.06×107 J (48,000 British thermal units) from a cold environment in 1.00 h. (a) What energy input in joules is necessary to do this if the airconditioner has an energy efficiency rating ( EER ) of 12.0?(b) What is the cost of doing this if the work costs 10.0 centsper 3.60×106 J (one kilowatt-hour)? (c) Discuss whether this cost seems realistic. Note that the energy efficiency rating ( EER ) of an air conditioner or refrigerator is defined to be the number of British thermal units of heat transfer from a cold environment per hour divided by the watts of power input.arrow_forward
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