# Motion And Force

• Apr 3rd 2009, 12:40 AM
siddscool19
Motion And Force
Can anyone tell me how to do Q 41 and 42..
• Apr 3rd 2009, 04:18 AM
marataya
Quote:

Originally Posted by siddscool19
Can anyone tell me how to do Q 41 and 42..

Q41 You should equate kinetic energy to potential energy so as the ball obtain enough kinetic energy to climb the largest circle (D=6R):

Q42 If mass is distributed equally along the length, then after swap potential energy of rope with mass m is decreased by mgl and of rope with mass 3m is increased by 3mgl.
• Apr 3rd 2009, 04:19 AM
CaptainBlack
Quote:

Originally Posted by siddscool19
Can anyone tell me how to do Q 41 and 42..

41. The minimum velocity (assuming negligable friction) corresponds to a KE equal to the potential energy of the particle when at the higest point of the tube.

CB
• Apr 3rd 2009, 04:22 AM
CaptainBlack
Quote:

Originally Posted by siddscool19
Can anyone tell me how to do Q 41 and 42..

42. You have raised a mass of 3m through l and lowered a mass of m through a distance l, so the potential energy change is the same as though you had raised a mass of 2m through a distance l.

CB