Question

A very flexible uniform chain of mass M and lengthL is suspended from one end so that it hangs vertically,the lower end just touching the surface of a table. the upper endis suddenly released so that the chain falls onto the table andcoils up in a small heap, each link coming to rest the instant itstrikes the table. find the force exerted by the table on the chainat any instant, in terms of the weight of chain already on thetable at that moment. Draw free body diagram showing all forcesacting.
[Hint: consider the momentum delivered to the table by the fallingchain between times t and t+dt. the chain is soflexible that links don't exert forces on one another; they're alljust in free fall]