Question

Two 20 g flat worms climb over a very thin wall 10 cm high. One of the worm is 20 cm long, the other is wider and only 10 cm long Which of them has done more work against gravity when half of it is bent over the top of the wall What is the ratio of amount of work done by two worms

Answer 1

Answer:

10cm worm has done more work against gravity.

The work done against gravity can be calculated from the increases in height of the centre of mass. The centre of mass of a worm folded in two is located at the middle of either half, i.e., at a point one-quarter of the worm's total length from one end, as given in the figure. Thus, the centre of mass of the narrow flat worm travels 5cm up the wall; while that of the board one moves 7.5cm. Hence, work done by 10cm worm is more against gravity. Also, the ratio of the work done is 2:3.