Question

air cannot be used in hydraulic press

Answer 1

Answer:

Hydraulic devices are preferred when large forces need to be generated in compact machines, meaning you need very high pressure differences. ... A gas is not used in hydraulic machines as the fluid because gas is easily compressible and so if a gas is used, the energy would mostly go into compressing a gas.

Explanation:

Answer 2

Answer:

Because air is compressible but water can't that's why water is used