Find the work a boy of weight 55 kg has to do against gravity when climbing from the bottom to the top of a 3.0 m high tree.

A ladder 2.5 m long and of weight 150 N has its centre of gravity 1 m from its bottom. A weight of 40 N is attached to the top end. The work required to raise the ladder from the horizontal position to the vertical position is

An escalator is 30.0 meters long and slants at 30.0^(@) relative to the horizontal. If it moves at 1.00 m/s, at what rate does it do work in lifting a 50.0-kg woman from the bottom to the top of the escalator ?

A boy of weight 25kg slides down a rope hanging from the branch of a tree. If the force of friction against him is 50N, the boy's acceleration is (g= 10 ms^(-2) )

A boy of weight 25kg slides down a rope hanging from the branch of a tree. If the force of friction against him is 50N, the boy's acceleration is (g= 10 ms^(-2) )

The horizontal distance between two trees of different heights is 60m.The angle of depression of the top of the first tree when seen from the top of the second tree is 45o .If the height of the second tree is 80m, find the height of the first tree.

How much work does a boy of mass 50kg do when he climbs a height 30 metre.

From a point on the ground,the angles of elevation of the bottom and the top of a transmission tower fixed at the top of a 20m high building are and and respectively.Find the height of the tower.

The horizontal distance between two trees of different heights is 60m. The angle of depression of the top of the first tree when seen from the top of the second tree is 45^o . If the height of the second tree is 80m, find the height of the first tree.