AP Physics AP Physics Fluid Mechanics & Energy Systems

Question 1

Pressure in a static fluid at depth h is given by:

Accepted Answer

P = ρgh

Answer

P = ρgh²

Answer

P = ρg/h

Answer

P = ρh

Question 2

Archimedes' principle states that the buoyant force on an object equals:

Accepted Answer

The weight of displaced fluid

Answer

The weight of the object

Answer

The density of the object times volume

Answer

The pressure times the object's surface area

Question 3

According to the continuity equation for an incompressible fluid, if pipe area decreases, fluid speed:

Accepted Answer

Increases

Answer

Decreases

Answer

Stays the same

Answer

Becomes zero

Question 4

Bernoulli's equation relates pressure, fluid speed, and height for:

Accepted Answer

Incompressible, non-viscous steady flow

Answer

Compressible, viscous flow

Answer

Turbulent flow only

Answer

Gases only

Question 5

In Bernoulli's equation, where fluid speed is greatest, the pressure is:

Accepted Answer

Lowest

Answer

Greatest

Answer

Unchanged

Answer

Equal to atmospheric

Question 6

A fluid of density 1000 kg/m³ flows through a pipe. If the cross-sectional area drops from 0.04 m² to 0.01 m² and initial speed is 2 m/s, what is the new speed?

Accepted Answer

8 m/s

Answer

0.5 m/s

Answer

2 m/s

Answer

4 m/s