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Unformatted text preview: Reflect: This would be an impossibly strenuous exercise session; the average calorie intake per day for a human is about 2700 food calories. 7.73. Set Up: Find the elapsed time in each case by dividing the distance by the speed, Then calculate the energy as Solve: Running: Walking: Reflect: The less intense exercise lasts longer. 7.74. Set Up: Your power is the rate of change of your potential energy, Take your mass to be 70 kg and assume you can run up a set of stairs, with a vertical height of 3.0 m, in 2.0 s. Solve: Converting to horsepower, Reflect: You are only slightly stronger than a horse that is working at a leisurely rate. And unlike the horse, you can- not keep up this pace for a long time period. 7.75. Set Up: For part (a), the work performed each day is where The mass of the blood is calculated using the density, and the known volume of The power output is then found from Solve: (a) The work performed in a single day is: (b) (c) Reflect: The heart actually puts out more power than the value calculated because two forms of energy were not...
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This note was uploaded on 03/06/2009 for the course PHYS 114 taught by Professor Shoberg during the Spring '07 term at Pittsburg State Uiversity.
- Spring '07