A uniform chain 10 m long and with mass 20 kg is hanging from the top of a building 10 m high. If a bucket filled with cement of mass 55 kg is attached to the end of the chain, how much work is required to pull the bucket and chain to the top of the building? (Assume g = 9.8 m/s2 )

A force of 45.6 lb is used to push a box 10.3 ft across a level floor. (a) How much work was done on the box? (b) What is the change of potential energy as a result of this move? (a) W = x 102 ft·lb %3D (b) PE = ft lb %3D

A bag of sand which acts as a counter weight for a stage set is suspended vertically by a rope of length L = 6.00 m and has a mass m = 132 kg. If a stagehand pushes the bag of sand a distance d = 5.00 m sideway: (a) the horizontal force needed in order to hold the bag at this position (b) the amount of work done on the bag by gravity as the stagehand pushes it to this position (Include the sign of the value in your answer.) (c) the amount of work done by the stagehand as he pushes the bag to this position (Include the sign of the value in your answer.)

A cable exerts a constant upward tension of magnitude 2.06 X 104 N on a 1.80 X 10³ kg elevator as it rises through a vertical distance of 4.10 m. (a) Find the work done by the tension force on the elevator (in J). (b) Find the work done by the force of gravity on the elevator (in J).