A hydraulic press is used to lift heavy objects, such as cars. It consists of a U-tube, one end having large cross-sectional area A1; and the other, small cross-sectional area A2. The tube is filled with an incompressible fluid, and the load is placed on a platform fitted to area A1. (See figure.)
The object is lifted by applying a force to a piston fitted to area A2. If the piston moves down a distance Δx2, then the load moves up a distance Δx1. These distances are small compared to the other dimensions of the device. We assume losses due to friction are negligible.
If the work done by the piston on the fluid is W2, and the work done by the fluid on the load is W1, which is correct?