Density

4 marks · Normal

Describe an experiment you could use to find the density of a small, irregular solid object such as a stone.

Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.

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Must show: Describe measuring mass (e.g., balance), Describe measuring volume (e.g., displacement in measuring cylinder), Explain calculation of density, Mention accurate reading and possible repeats

Also accept: Use of overflow can for volume

Common mistakes: Not explaining how to measure volume of an irregular object

Show mark scheme and worked solution

Marking points

M1 · 1 mark · Describes measuring mass using a balance.

M2 · 1 mark · Describes finding volume by water displacement in a measuring cylinder or overflow can.

M3 · 1 mark · States calculation: density = mass / volume.

B1 · 1 mark · Mentions accuracy/repeats or precautions.

Worked solution

1. Measure the mass of the stone with a digital balance.

2. Partially fill a measuring cylinder with water and note initial volume.

3. Carefully place the stone in the cylinder. Record the new volume.

4. The volume of the stone = final volume - initial volume.

5. Calculate density using: .

6. Repeat to improve accuracy.