Compound measures combine two different units. The most common are speed (distance/time), density (mass/volume), and pressure (force/area).
Core Formulas
Density
Units: g/cm³ or kg/m³.
Pressure
Units: N/m² (Pascals) or N/cm².
Population Density
Worked Example: Density
Problem
Mass = 450g, Volume = 50 cm³. Density = g/cm³.
Solution
Worked Example: Pressure
Problem
Force = 600 N, Area = 0.5 m². Pressure = N/m².
Solution
Worked Example: Finding Volume
Problem
Density = 2.7 g/cm³, Mass = 135g. Volume = cm³.
Solution
Practice Problems
- Mass 200g, volume 25 cm³. Find density.
- Density 8 g/cm³, volume 15 cm³. Find mass.
- Force 500 N, pressure 250 N/m². Find area.
Want to check your answers and get step-by-step solutions?
Key Takeaways
Density = Mass ÷ Volume.
Pressure = Force ÷ Area.
Rearrange the triangle: cover what you want, the remaining gives the formula.
Watch units — ensure consistency.