2a) speed at point B, v = sqrt(2*KE/m)
= sqrt(2*mgh/m) where h is change in height
= sqrt(2*8.35*9.8*(6.2-3.2)/8.35)
= 7.668 m/s
b) Net work done by gravity = mgh where h is change in height
= 8.35*9.8*(6.20-2)
= 343.7 J
3a) work required to be done = mg sin theta *d
= 85*9.8*sin 42 degree*83
= 46263 J
3b] power = force*velocity
= mg sin theta *v
= 85*9.8*sin 42 degree*5.7
= 3177 W
2. A bead of mass m = 8.35 kg is released from point A and slides...
Sample Problems (Ch.5 Energy) 1A71.4 kg base runner begins his slide into second base when he is moving at a speed of 5-3 m/s. The coefficient of friction between his clothes and Earth is 0.78. He slides so that his speed is zero just as he reaches the base. (a) How much mechanical energy is lost due to friction acting on the runner? (b) How far does he slide? 2. A bead of mass m = 8.35 kg is released...
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