As I understand it, pulleys will reduce the force needed to lift objects but require a greater distance. As the number of pulleys increase, the force decreases. But for all cases of pulleys, the work required to lift a given object to a given height will always remain the same. When I attach mass directly to the axel of a pulley, and have one end of a rope attached to a support beam while I pull up on the other end of the rope, the pulley with the attached mass will rise. Each end of the rope should feel a force which is half that of the weight of the attached mass. Say the attached mass has a weight of 10 newtons and I want to actual mass to be lifted 1 meter above the ground. Work done against gravity is 10 joules. When I actually go to do this with the pulley setup I described above, I find that I am pulling up my end of the rope with 5 newtons and I have to pull up a total of 1 meter of rope to get the mass 1 meter above the ground. The work I have done seems to be 5 joules... Why is this? I thought I should be doing 10 joules of work. This seems to be requiring only half of the total work needed. I am taking all of my measurements very accurately and I am sure there is no problems with them.