10/27/10 1 Physics 12110/27/10 2 Physics 1216.1 6.2 6.3 6.4 a 23% 1% 82% 46% b 4% 5% 18% 13% c 41% 9% 0% 36% d 64% 11% 5% e 39% 74% f 2% 10/27/10 3 Physics 12110/27/10 9 Physics 121 (12mv2) =Fnet r = kxxIf x is changing over the intervalwhat x should we use? = kxx = kxi+ xf2xf xi()= 12kxf2 xi2()= 12kx2()x10/27/10 10 Physics 121 (12mv2+12kx2) = 0Us=12kx210/27/10 11 Physics 121 lose KE gain KE lose KE both ways Gravity: Conservative Friction: Non-Conservative10/27/10 12 Physics 121 rFmvnetall= )21(2rFrFmvnetcnonnetcons + =)21(210/27/10 13 Physics 121 212()netnon Cmv U F r += rFrFmvnetcnonnetcons + =)21(2(12mv2) = U + F non cnet r10/27/10 14 Physics 12110/27/10 15 Physics 121 (12mv2+ mgh +12kx2) = 012mvi2+ mghi+12kxi2=12mvf2+ mghf+12kxf2Mechanical10/27/10 16 Physics 12110/27/10 17 Physics 12110/27/10 18 Physics 121 Power =Energy changetime to make the change=Wt= F net r t= F net v (for mechanical work)10/25/10 20 Physics
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