A 10 ft chain weighs 75 lb and hangs from a ceiling. Find the work done (in ft-lb) in lifting the lower end of the chain to the ceiling so that it's level with the upper end.

11. A 5kg block is pushed up a 40° incline at constant velocity of 3m/s. The force pushing on the blockacts parallel to the incline, and has a magnitude of 47.5N. (a) What is the magnitude of the normal forceacting on the block? (b) What is the magnitude of the frictional force? (c) Calculate the coefficient offriction. (d) How much work is done by the normal force? (e) How much work is done by the force offriction after 4 seconds have elapsed? (f) What is the net work done on the block?

A horizontal force of 150 N is used to push a 41.5-kg packing crate a distance of 6.05 m on a rough horizontal surface. If the crate moves at constant speed, find each of the following. (a) the work done by the 150-N force (b) the coefficient of kinetic friction between the crate and the surface

A driver of a car traveling at 52 km h¹ applies the brakes and accelerates uniformly in the opposite direction. The car stops in 5 s. Another driver going at 3 km h¹ in another car applies his brakes slowly and stops in 10 s. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars traveled farther after the brakes were applied?

13-

Suppose that as part of their training, the football players of Central Luzon State University went up a stair in 66 s. The length of the stair is 140 m and inclined at 32°. Calculate the average power required for a player of mass 95 kg.

Calculate the work done (in J) on a 1550 kg elevator car by its cable to lift it 37.5 m at a constant speed, assuming friction averages 115 N.   What is the total work done (in J) on the lift?

An electric elevator with a hoist at the top has a steel cable which weigh 3kg/m. The total height of the elevator is 30 m from the basement to the top floor. Assuming that the cable is completely wound on to the motor when the elevator is in the top floor position, determine the total work done in lifting 500 kg load from the basement to the top floor 15.

A  6.8kg block is being pushed up a frictionless plane inclined at  35o to the horizontal. (a) Calculate the work done by the normal force (b) Calculate the work done by the gravitational force as the block moves  3.6m along an axis parallel to the inclined plane.

A man drags a table 3.75 m across the floor, exerting a constant force of 46.0 N, directed 29.0° above the horizontal. (a) Find the work done by the applied force.(b) How much work is done by friction? Assume the table's velocity is constant.