Static Fluids
5 questionsKey ideaPressure in a fluid increases with depth: P = P₀ + ρgh. It depends only on the depth, not on the container’s shape.
Common mistakeThinking a wider container has a higher pressure at the same depth.
AP Physics 1 · Unit 8
Fluids practice quiz
Practice pressure, buoyancy, continuity, and Bernoulli’s equation. Quiz one topic at a time or take the whole unit.
- 20 questions
- 4 topics
- 3 FRQs
- Hints and explanations
Topics in this unit
The idea each topic turns on, and the mistake students make most often.
Buoyancy
5 questionsKey ideaThe buoyant force equals the weight of the fluid displaced: FB = ρfluidVsubmergedg.
Common mistakeUsing the object’s density or mass instead of the fluid’s density and the displaced volume.
Continuity
5 questionsKey ideaFor an incompressible fluid, the volume flow rate Av is the same everywhere along a pipe, so the fluid speeds up where the pipe narrows.
Common mistakeScaling the area with the diameter instead of the diameter squared: halving a pipe’s diameter makes the fluid move four times faster, not twice.
Bernoulli's Equation
5 questionsKey ideaAlong a streamline, P + ½ρv² + ρgh is constant: at the same height, faster flow means lower pressure; at the same speed, higher elevation means lower pressure.
Common mistakeForgetting the height term when the pipe rises, or the speed term when its cross-section changes.
Try a sample question
This is one of the 20 questions in the Unit 8 quiz.
Static Fluids
Which equation gives the pressure at depth h in a static fluid?
- AP = P₀ + ρgh
- BP = P₀ − ρgh
- CP = ρVg
- DP = m/V
Show the answer and explanation
Answer: A. P = P₀ + ρgh
The pressure in a static column of fluid is P = P₀ + ρgh, where P₀ is the pressure at the fluid surface.
Free-response practice
AP-style FRQs for this unit. Students score themselves point by point against a rubric and see a full solution.