A ladder is at rest with its upper end against a wall and the lower end on the ground. Is the ladder more likely to slip, when a man stands on it at the bottom or a the top? Give reason.

A ladder is kept standing at a slanting position against a wall of a house and in this position the base of the ladder is at a distance of 9.5m from the wall.If the ladder makes an angle of 60^@ with the ground level,find the length of the ladder.

A 70 kg man stands in contact against the inner wail of a hollow cylindrical drum of radius 3 m rotating about its vertical axis with 200 rev/min. The coefficient of friction between the wall and his clothing is 0.15. What is the minimum rotational speed of the cylinder to enable the man to ' remain stuck to the wall (without falling) when the floor is suddenly removed?