Pressure in Liquids — Depth and Upthrust
Part of Gas Pressure & Temperature — GCSE Physics
This deep dive covers Pressure in Liquids — Depth and Upthrust within Gas Pressure & Temperature for GCSE Physics. Revise Gas Pressure & Temperature in Particle Model for GCSE Physics with 13 exam-style questions and 30 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 4 of 12 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 4 of 12
Practice
13 questions
Recall
30 flashcards
🔬 Pressure in Liquids — Depth and Upthrust
Figure 2: Pressure increases with depth in a fluid. Greater depth means more liquid above pushing down.
P = ρ × g × h — Pressure in a liquid increases with depth. At greater depths, more liquid above pushes down. Upthrust (buoyancy) is the upward force on an object in a fluid, equal to the weight of fluid displaced. If upthrust ≥ weight, the object floats!
Quick Check: A gas is heated in a sealed, rigid container. Explain, using the particle model, why the pressure increases.
Heating the gas increases the kinetic energy of the particles, so they move faster. This causes more frequent collisions with the container walls, and each collision is harder (more force). The increased rate and force of collisions means greater pressure on the walls.