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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