228 Potential EnergyP8.25(a)Fij=+300500.±.±ejNmW==−−=−4002003 00 2 005 00 3 009 00..±.±.....kgmJrijafafThe result does not depend on the path since the force is conservative.(b)WK=∆−=−FHGIKJ9002222....vafso v=−=32 0 9 00339.. ms(c)∆UW=JSection 8.4Changes in Mechanical Energy for Nonconservative ForcesP8.26(a)UKKUfifi=− +Uf=−+=30 0 18 0 10 022 0....JE=40 0J(b)Yes, ∆∆∆EKUmechis not equal to zero. For conservative forces +=0.P8.27The distance traveled by the ball from the top of the arc to the bottom is πR. The work done by thenon-conservative force, the force exerted by the pitcher,isEFrFR=°=cos0.We shall assign the gravitational energy of the ball-Earth system to be zero with the ball at the
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This note was uploaded on 12/14/2011 for the course PHY 203 taught by Professor Staff during the Fall '11 term at Indiana State University .