hmwk6 - 4. Many athletic activities require more power than...

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Homework #6 Due midnight Sunday October 30. 1. Changes in energy for the human body can be described by the equation: Change in Internal Energy = Chemical Energy - Mechanical Work - Dissipated Heat . (1) Connect each of the following activities with a term in this equation. (Explain your selections.) (a) Eating (b) Sweating (c) Running stairs (d) Gaining weight 2. Athletes use various techniques to go fast. Give a sports example for each technique. (a) Make the forces of friction and fluid resistance small. (b) Make the velocity of the contact point with the ground small. (c) External power source. (d) Convert potential energy to kinetic energy 3. About how much power can an athlete produce? (Make a very rough estimate in watts. Hint: consider the bicycle generator demonstration in class or multiply the human power output curve in the lecture notes by the appropriate quantity.)
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Unformatted text preview: 4. Many athletic activities require more power than can be generated aero-bically. (a) (Approximately) how long can a person sustain very strenuous ac-tivity? Give a sports example to support your answer. (b) In many sports, these bursts of power are interspersed with intervals of rest. (Approximately) what percentage of the time must the ath-lete rest to sustain repeated bursts of peak activity? Give a sports example to support your answer. Warmup Questions Submit answers by 11:00 p.m. Monday October 31. 1. Warmup question for November 1. In racketball, backspin makes the ball drop down from the wall faster. Why does this work? 2. Warmup question for November 3. If a weightlifter jerks a barbell, is it best to have the weight close to the body or out at arms length? Why? 1...
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This note was uploaded on 12/12/2011 for the course PHYS 17 taught by Professor Mcwilliams,r during the Fall '08 term at UC Irvine.

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