If we wanted to calculate the minimum or critical velocity needed for the block to just be able to pass through the top of the circle without the rope sagging then we would start by letting the tension in the rope approaches zero.
http://img147.imageshack.us/img147/6826/3c6634a694b3434387bd810.gif [Broken]http://img147.imageshack.us/img147/7402/3c46cefd59484d479f07621.gif [Broken]http://img147.imageshack.us/img147/4192/5ee60dbd561d4cca96b54d5.gif [Broken]
why must we letting the tension in the rope approaches zero without the rope sagging? what is the force support the object goes to the top without pulling down by gravitation force? was it because of the newton first law, so the object wanted to remain straight line but pulling towards to the centre by centripetal force?
At point B, why the normal reaction force is or need to be zero? isn't the mg is acting on the track?
will it due to the inertia of the roller-coaster tends to go straight yet pulling back the centripetal force,mg. hence, the contact force to the track is reduced and almost zero since the roller-coaster is really fast.
Hope somebody could answer these to me, thank you
Last edited by a moderator: