Describe how you would find the density of a stone using a spring balance and a measuring cylinder. How does the result tell you whether the stone floats on water?
How to lay out the answer. Follow the frame, then write it in your own words.
1 · State the idea. Density = mass ÷ volume, so find the mass and the volume separately.
2 · Find the mass. Hang the stone from a spring balance set to zero, and read its mass m.
3 · Find the volume. Note the water level V₁ in a measuring cylinder. Lower the stone in fully and read V₂. Volume V = V₂ − V₁.
4 · Draw the cylinder. [Diagram: measuring cylinder with water, the stone on a thread fully under water, levels V₁ and V₂ marked]
5 · Calculate. Density d = m/V, in g cm⁻³.
6 · Predict. If d is more than 1 g cm⁻³ (water), the stone sinks; if it is less, the stone floats.
Scoring tip: Read the water level at the bottom of the curved surface, with your eye level with it. Keep the stone fully under water and clear of the sides.
