Learn to measure area, volume, and density, and understand the units used for each physical quantity.
Area measures surface extent (units: m², cm²). Volume measures the space an object occupies (units: m³, cm³, or litres for liquids).
Find the area of a rectangle 8 cm by 5 cm.
8×5=40 cm²
Find the volume of a cube with side 4 cm.
4³=64 cm³
Density = mass/volume, measured in g/cm³ or kg/m³. It tells us how tightly packed the matter is in an object.
A metal block has mass 200g and volume 25 cm³. Find its density.
200/25=8 g/cm³
Why does an object with lower density than water float on water?
Because it has less mass per unit volume, so it displaces water with a weight equal to its own, remaining buoyant
1. Find the area of a square with side 6 cm.
2. Find the volume of a cuboid 5cm×4cm×3cm.
3. A liquid has mass 150g and volume 100 cm³. Find its density.
4. What is the SI unit of density?
5. An object has density 0.8 g/cm³. Will it float or sink in water (density 1 g/cm³)?