Pressure in Fluids

IGCSE Edexcel Physics
5.5-5.7 Pressure
Key Concepts: $p = F/A$ and $p = h\rho g$. Pressure in fluids acts in all directions.

Section A: Concepts

1. Explain why pressure in a liquid acts equally in all directions. [2]

Section B: Calculations

2. A force of 300 N acts on an area of $0.6\,m^2$. Calculate pressure. [2]
3. Calculate pressure at 5 m depth in water ($\rho = 1000\,kg/m^3$, $g = 9.8\,N/kg$). [3]
Total marks: 7

Mark Scheme

1. Pressure from particle collisions acts equally in all directions [2]
2. $p = F/A = 300/0.6 = 500\,Pa$ [2]
3. $p = h\rho g = 5 \times 1000 \times 9.8 = 49{,}000\,Pa$ [3]