经典力学题Ifsomeoneonearthfoundamotionlessisolatedropereachingverticallyupintotheskyandhangingdownnearlytotheground,couldtherebeanexplanationinagreementwiththewell-knownlawsofphysics?Ifso,howwouldtheropenee

Question

经典力学题
If someone on earth found a motionless isolated rope reaching vertically up into the sky and hanging down nearly to the ground ,could there be an explanation in agreement with the well-known laws of physics?If so,how would the rope need to be?

Answer 1

LZ是清华的吧?老毕的作业?
It is possible,theoretically.For the inner part of the rope,gravity is greater than fictitious centrifugal force,thus dragging it towards Earth; for the outer part of the rope,fictitious centrifugal force is greater than gravity,thus pulling it away from Earth.These two tendencies can cancel each other out if given an appropriate length of the rope.
Try integrating the net force along the rope.The integration should be zero,and solve this equation you will get the length of the rope.