Core Practical: Determining Density Flashcards

All 5 cards in this deck

What are the steps to find the density of an irregular solid by displacement?
e.g. a lump of iron

1. Measure its mass on a balance.
2. Part-fill a measuring cylinder with water, note the reading, immerse the solid and note the new reading; the difference is the volume.
3. Calculate density = mass ÷ volume.

What are the steps to find the density of a liquid?
e.g. 25 cm³ of cooking oil

1. Put the empty measuring cylinder on the balance and zero (tare) it.
2. Add the liquid; record its mass from the balance and its volume from the scale (read at eye level).
3. Calculate density = mass ÷ volume.

Which measurements are needed to find the density of a regular solid block?

Its mass with an electronic balance, and its length, width and thickness with a ruler (volume = $l \times w \times t$).

Why can the displacement method not be used to find the volume of a piece of wood?

The density of wood is less than that of water, so it floats — less water is displaced than the volume of the wood.

How many cubic metres are there in 1 cm³?

$1 \times 10^{-6}$ m³ (0.000001 m³), because 1 m = 100 cm, so 1 m³ = 100 × 100 × 100 cm³.