Why is the fulcrum on the axle and the wheelbarrow cart pivot in the car and the ground contact points?
On this question the fulcrum of the choice is casual space at any point can be used as a fulcrum and the wheelbarrow pivot in the wheel center, moving pulley fulcrum on the side, it is easy to solve, so don't know say you didn't understand.
For example, the fulcrum of the moving pulley is selected in the center, then the gravity will have no arm, and can only get the same result of pulling the rope on both sides of the pulley, but the tension can be obtained on the edge, which is the result of gravity 1/2.
