Pass Check: Compound Measures
Speed, density and pressure: rearranging the formula triangle and using correct units.
Compound measure
A measure made from two other quantities, like speed (distance and time).
Density
Mass per unit volume of a substance, measured in g/cm³ or kg/m³.
Pressure
Force per unit area, measured in pascals (Pa) or N/m².
Formula triangle
A memory tool showing how to rearrange a compound measure formula.
Quick check
Mixed quiz
1. An object has a mass of 75 g and a volume of 30 cm^3. Calculate its density, to 2 decimal places.
2. Which unit is correct for density?
3. A train travels 180 km in 2 hours. Calculate its average speed.
4. A train travels 120 km in 2 hours. Calculate its average speed.
5. Which formula correctly finds time?
6. A train travels 170 km in 2 hours. Calculate its average speed.
7. An object has a mass of 55 g and a volume of 22 cm^3. Calculate its density, to 2 decimal places.
8. An object has a mass of 80 g and a volume of 32 cm^3. Calculate its density, to 2 decimal places.