ch 7 hw 4 - the right side (the W ext side, energy inputs...

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Web Assign Ch7 HW4 f10 (Homework) Ashlyn Baum Physics 303K, section B, Fall 2010 Instructor: Jim Chelikowsky Current Score : 14 / 14 Due : Sunday, October 31, 2010 11:30 PM CDT 1. 6/6 points Question: MI3 7.9.X.042 Review of the woman, the barbell, and the Earth (Section 7.9 in the textbook). Starting from rest, a woman lifts a barbell with a constant force F through a distance h , at which point she is still lifting, and the barbell has acquired a speed v . Let E woman stand for the following energy terms associated with the woman: E woman = E chemical,woman + K woman (moving arms etc.) + U grav,woman+Earth + E thermal,woman The change in the kinetic energy of the barbell is (1/2) mv 2 - 0 = (1/2) mv 2 . The general statement of the energy principle is E sys = W ext . We'll consider terms on the left side of the equation (the E sys side, changes in the energy inside the system) and terms on
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Unformatted text preview: the right side (the W ext side, energy inputs from the surroundings). I. System: Woman + barbell + Earth For the system consisting of the woman, the barbell, and the Earth, which of the following terms belong on the left side of the energy equation (the E sys side)? For the system consisting of the woman, the barbell, and the Earth, which of the following terms belong on the right side of the energy equation (the W ext side)? The due date for this assignment is past. Your work can be viewed below, but no changes can be made. View Key none of these terms (left side is 0)-(1/2) mv 2 E woman Fh + mgh-mgh-Fh (1/2) mv 2 Page 1 of 1 Ch7 HW4 f10 11/21/2010 http://www.webassign.net/v4cgiashlyn@utexas/student.pl?k=20101121222654ashlyn@ut. .....
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This note was uploaded on 11/21/2010 for the course PHY 56665 taught by Professor Chelikowsky during the Fall '10 term at University of Texas at Austin.

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