Edexcel IGCSE Physics: Density and Pressure

Vocabulary practice flashcards covering mechanical pressure in solids and pressure differences in liquids according to the Edexcel IGCSE Physics specification.

Pressure

The force acting per unit area, at right angles to a surface, calculated using the equation $\text{pressure} = \frac{\text{force}}{\text{area}}$.

Pascal ($\text{Pa}$)

The SI unit of pressure, defined such that $1\,\text{pascal (Pa)} = 1\,\text{newton per square metre (N/m}^2\text{)}$.

Area and Pressure Relationship

The principle that for a constant force, spreading the force over a smaller surface area creates a much higher pressure, while spreading it over a larger area creates a lower pressure.

Formula for Pressure in Solids

$p = \frac{F}{A}$, where $p$ represents pressure in pascals ($\text{Pa}$), $F$ represents force in newtons ($\text{N}$), and $A$ represents surface area in square metres ($\text{m}^2$).

Formula for Pressure in Liquids

$p = h\rho g$, where $p$ is the pressure due to the liquid, $h$ is the depth, $\rho$ is the density of the liquid, and $g$ is the gravitational field strength.

Depth and Liquid Pressure

The principle stating that pressure in liquids increases directly with depth due to the increasing weight of the liquid above.

Density and Liquid Pressure

The relationship showing that at any fixed depth, a liquid with greater density exerts a higher pressure than a liquid with lower density.

Direction of Liquid Pressure

The physical rule stating that pressure at a given point in a liquid acts equally in all directions.