Question

which of the following defines hydraulics?
a) force pushing the piston against the brake fluid.
b) the resistance of two objects moving against each other.
c) science of using liquids to perform work.
d) the ability of the tires to supply friction.

Explanation:

Hydraulics is the science of using liquids to perform work. Option A is just a specific example related to a part of a hydraulic - like situation (in brakes) but not the general definition. Option B describes friction, not hydraulics. Option D is about tire friction, not related to the use of liquids for work.

Answer:

C. Science of using liquids to perform work.