Three irregular stone samples

PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Fluids · Fluids

Problem

Three irregular stone samples, labelled

A

B

and

C

, are examined in the laboratory. Masses measured in air:

A = 250\,\text{g}

B = 350\,\text{g}

C = 150\,\text{g}

Volumes found by water displacement:

A = 90\,\text{cm}^3

B = 45\,\text{cm}^3

C = 160\,\text{cm}^3

Densities of common rocks for reference: Granite:

2.7\times10^{3}\,\text{kg m}^{-3}

Basalt:

3.0\times10^{3}\,\text{kg m}^{-3}

Pumice:

0.9\times10^{3}\,\text{kg m}^{-3}

Density of kerosene:

0.8\times10^{3}\,\text{kg m}^{-3}

(i) Calculate the density of each stone sample in

\text{kg m}^{-3}

. (ii) Arrange the three samples in descending order of density. (iii) Match each sample

A

B

and

C

with the most likely rock type from the reference list, giving reasons for your choice. (iv) If the three stones are dropped into kerosene, predict which of them will float and which will sink. Justify your answer using the calculated densities.

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