Which of the following is a word that describes fluid systems that apply Pascal's principle?Push liftsAir pressureMneumatics AeronauticsHydraulics

To determine which word describes fluid systems that apply Pascal's principle, let's analyze each option:

1. Push lifts: This term does not specifically describe a fluid system.
2. Air pressure: This is a concept related to fluids but does not describe a system.
3. Mneumatics: This seems to be a misspelling. The correct term is "Pneumatics," which involves the use of gas (usually air) to transmit power.
4. Aeronautics: This term relates to the study or practice of travel through the air, not specifically fluid systems.
5. Hydraulics: This term refers to the use of liquid (usually oil or water) to transmit power in fluid systems.

Pascal's principle states that pressure applied to a confined fluid is transmitted undiminished throughout the fluid. Both pneumatics and hydraulics apply this principle, but the question asks for a word that describes fluid systems, and hydraulics is more commonly associated with liquid systems.

Therefore, the correct answer is Hydraulics.