Energy is conventionally measured in Calories as well as in joules.One Calorie in nutrition is 1 kilocalorie, which we define inChapter 11 as 1 kcal = 4,186 J. Metabolizing 1 gram of fat canrelease 9.00 kcal. A student decides to try to lose weight byexercising. She plans to run up and down the stairs in a footballstadium as fast as she can and as many times as necessary. Is thisin itself a practical way to lose weight? yes no To evaluate the program, suppose she runs up a flight of90 steps, each 0.150 m high, in67.0 s. For simplicity, ignore theenergy she uses in coming down (which is small). Assume that atypical efficiency for human muscles is 20.0%. This means that whenyour body converts 100 J from metabolizing fat, 20 J goes intodoing mechanical work (here, climbing stairs). The remainder goesinto internal energy. Assume the students

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Energy is conventionally measured in Calories as well as in joules.One Calorie in nutrition is 1 kilocalorie, which we define inChapter 11 as 1 kcal = 4,186 J. Metabolizing 1 gram of fat canrelease 9.00 kcal. A student decides to try to lose weight byexercising. She plans to run up and down the stairs in a footballstadium as fast as she can and as many times as necessary. Is thisin itself a practical way to lose weight?  yes  no  To evaluate the program, suppose she runs up a flight of90 steps, each 0.150 m high, in67.0 s. For simplicity, ignore theenergy she uses in coming down (which is small). Assume that atypical efficiency for human muscles is 20.0%. This means that whenyour body converts 100 J from metabolizing fat, 20 J goes intodoing mechanical work (here, climbing stairs). The remainder goesinto internal energy. Assume the students

Maciej Morrow · Accepted Answer

a) the amount of energy released by burning 1 lb offat is 1 lb (453.8 g / 1lb)(9 K cal / 1g)(4186J/1Kcal)= 1.71 × 107J mechanical energy out put is 1.71 × 107J (0.20) = n mg (no .of steps)height cos 0o 1.71 × 107J (0.20) = n (57.0 kg)(9.8 mis2)(90) (0.150 m )number of times she must climb the steps is n = [1.71 × 107J (0.20)] /(57.0 kg)( 9.8 mis2)(90 )(0.150m) simplify the above youwill get the answer b) power output P = W/t = [ (57.0 kg)( 9.8 mis2)(90 )(0.150m)]/ 67.0 s simplify for the answer 1 h p = 746 W

Energy is conventionally measured in Calories as well as in joules.One Calorie in nutrition is 1 kilocalorie, which we define inChapter 11 as 1 kcal =

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