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Unformatted text preview: Patel (sap785) – Homework #4 – shubeita – (58645) 1 This printout should have 5 questions. Multiplechoice questions may continue on the next column or page – find all choices before answering. 001 10.0 points A student weighing 700 N climbs at constant speed to the top of an 8 m vertical rope in 10 s. The average power expended by the student to overcome gravity is most nearly 1. P = 875 W. 2. P = 5 , 600 W. 3. P = 1 . 1 W. 4. P = 87 . 5 W. 5. P = 560 W. correct Explanation: P = W t = F d t = (700 N) (8 m) 10 s = 560 W . 002 10.0 points A force vector F ( x, t ) = ˆ ı b t x acts on an object, where b is the constant 10 N / m · s. When the object is at x = 5 m at t = 2 sec, its velocity v = ˆ ı (4 m / s) +ˆ (10 m / s). At this moment, what power is being deliv ered by the force? 1. 100 Watts 2. 10 Watts 3. 300 Watts 4. 400 Watts correct 5. 800 Watts 6. 50 Watts 7. Zero because the object’s velocity is in stantaneously constant....
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This note was uploaded on 04/16/2010 for the course PHY 317k taught by Professor Kopp during the Spring '07 term at University of Texas.
 Spring '07
 KOPP

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