State if the following quantity are positive, negative or zero:
(a) work done by a man in lifting a bucket out of a well by means of a rope tied to the bucket
(b) work done by gravitation in the above case
(c) work done by
Work done by man is positive as force and displacement are in the same direction.
Work done by gravitation is negative as force and displacement are in opposite directions.
Work done by friction is negative as friction acts up the plane as the body slides down the place.