Measuring density

O/L Science · G.C.E. Ordinary Level · Grades 10–11

Aim

To find the density of solids from their mass and the water they displace.

Apparatus

• An electronic balance
• Measuring cylinder and water
• Several solid objects

Method

1. Weigh the object to find its mass m.
2. Note the water level in the cylinder.
3. Lower the object in and read again: V = the difference.
4. Calculate density = m ÷ V.

Conclusion

The density of a material is constant (aluminium ≈ 2.7 g cm⁻³). Objects less dense than water (1 g cm⁻³) float.