1. A chain of mass 20 kilograms and length 10 metres initially lies on the ground. Let P be the fixed point on the chain which is 7 metres from one end of chain.

(a) Assuming that frictional forces are negligible USE INTEGRATION in order to determine the minimum amount of work done in lifting the chain (at point P) so that the final position of point P is a height of 5 meters above ground level.

My attempt:

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