ASVAB (Armed Services Vocational Aptitude Battery)Mechanical Comprehension (MC)Easy

A mechanic is inspecting a car engine's cooling system. The system uses a pump to circulate coolant. What fundamental principle describes how this pump creates fluid flow?

  1. ANewton's Third Law of Motion
  2. BArchimedes' Principle
  3. CConservation of Energy
  4. DBernoulli's Principle
Show answer & explanation

Correct answer: D. Bernoulli's Principle

Bernoulli's Principle explains that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. A pump creates flow by increasing fluid speed, thereby decreasing pressure.

Why the other options are wrong

  • A. Newton's Third Law relates to action-reaction forces, not the internal dynamics of fluid flow in a pump.
  • B. Archimedes' Principle relates to buoyancy, not fluid flow generated by a pump.
  • C. While conservation of energy applies, Bernoulli's Principle is the specific application for fluid dynamics in this context.

Bernoulli's Principle

States that an increase in the speed of a fluid occurs simultaneously with a decrease in static pressure or a decrease in the fluid's potential energy.

  • Applies to fluids in motion (liquids and gases).
  • Explains how aircraft wings generate lift and how pumps create flow.
  • Derived from the principle of conservation of energy.

Memory trick: Fluid's fast flow means pressure's low.

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