小弟在作Halliday時碰到兩題問題,希望各位高手能夠幫忙解答 問題是在第七版第11章 8. A solid brass ball of mass 0.280g will roll smoothly along a loop-the-loop track when released from rest along the straight section. The cricular loop has radius R = 14.0cm, and the ball has radius r << R. (a) What is h if the ball is on the verge of leaving the track when it reaches the top of the loop? If the ball is released at height h = 6.00R, what are the (b) magnitude and (c) direction of the horizontal force component acting on the ball at point Q? 64. A bowler throws a bowling ball of radius R = 11cm along a lane. The ball slides on the lane with initial speed Vcom,0 = 8.5m/s and initial angular speed w0 = 0. The coefficient of kinetic friction between the ball and the lane is 0.21. The kinetic frictional force fk acting on the ball causes a linear acceleration of the ball while producing a torque that causes an augular acceleration of the ball. When speed increased enough, the ball stops sliding and then rolls smoothly. (a) What then is Vcom in term of w ? During the sliding, what are the ball's (b) linear acceleration and (c) angular acceleration ? (d) how long does the ball slide ? (e) How far does the ball slide ? (f) What is the linear speed of the ball when smooth rolling begins ? --

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