Topic 5 - Solids, Liquids and Gases

Question 1

The equation is ρ = m / v, but what are the units and rearrangements?

Answer 1

ρ = m / v
m = ρ x v
v = m / ρ

ρ = density (kg/m³)
m = mass (kg)
v = volume (m³)

Question 2

The equation is p = f / a, but what are the units and rearrangements?

Answer 2

p = f / a
f = p x a
a = f / p

p = Pressure (Pascals, Pa)
f = Force (Newtons, N)
a = Area (m²)

Question 3

How does pressure at a point in a gas or liquid at rest act?

Answer 3

It acts equally in all directions.

Question 4

The equation is p = h x ρ x g, but what are the units and rearrangements?

Answer 4

p = h x ρ x g
h = p / ρ x g
ρ = p / h x g
g = p / h x ρ

p = pressure difference (Pascals, Pa)
h = height (metres, m)
ρ = density (kg/m³)
g = gravitational field strength (N/Kg)