Principles of Fluid Mechanics Flashcard

Front

What principle explains lift on airplane wings?

Back

Bernoulli’s Principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure. This principle explains how air moves faster over the top of an airplane wing, creating lift.

Front

Why do car brakes work?

Back

Pascal’s Principle states that when pressure is applied to a confined fluid, the pressure change occurs throughout the fluid. This principle is the basis for hydraulic brakes in cars.

Front

What happens to fluid speed when the cross-sectional area of a pipe decreases?

Back

According to the Continuity Equation, if the cross-sectional area decreases, the fluid speed must increase to maintain the same flow rate.

Front

Why is water faster in narrower stream sections?

Back

Velocity increases as area decreases due to the principle of conservation of mass, which states that the mass flow rate must remain constant.

Front

What happens to an airplane wing when air pressure is lower above it than below it?

Back

The wing will move upward due to the difference in pressure, as the higher pressure below pushes the wing up.

Front

Define Bernoulli’s Principle.

Back

Bernoulli’s Principle states that in a flowing fluid, an increase in velocity occurs simultaneously with a decrease in pressure or potential energy.

Front

What is Pascal’s Principle?

Back

Pascal’s Principle states that a change in pressure applied to an enclosed fluid is transmitted undiminished to all portions of the fluid and the walls of its container.

Front

Explain the Continuity Equation in fluid mechanics.

Back

The Continuity Equation states that for an incompressible fluid, the mass flow rate must remain constant from one cross-section of a pipe to another, leading to the relationship A1V1 = A2V2, where A is the cross-sectional area and V is the fluid velocity.

Front

What is the relationship between pressure and fluid speed according to Bernoulli’s Principle?

Back

As the speed of a fluid increases, the pressure within the fluid decreases.

Front

How does surface tension affect fluid behavior?

Back

Surface tension is the cohesive force at the surface of a liquid that causes it to behave as if it were covered with a stretched elastic membrane, affecting how fluids interact with solids.