Cambridge International AS Level · Marine Science (9693)

Density and pressure: Practice Questions

2 multiple-choice questions marked as you go, and 4 written questions with worked solutions. All on Density and pressure.

6 questions19 marksFree, no account

Question 1

1 mark

A sample of sea water has a mass of \(1025\text{ kg}\) and occupies a volume of \(1.0\text{ m}^{3}\). Using the formula \(\text{density} = \text{mass} \div \text{volume}\), what is the density of this sample?

Question 2

1 mark

In polar regions, a layer of ice often forms on the surface of the ocean. Which statement best explains why this ice floats on the liquid sea water?

Question 3

3 marks

Explain why ice floats on the surface of the ocean and state one biological importance of this property for marine organisms.

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Question 4

5 marks

Describe the formation of a halocline in the water column and explain how the resulting density gradient prevents the vertical mixing of nutrients between ocean layers.

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Question 5

3 marks

Explain how temperature and salinity interact to influence the density of surface waters compared to the deep ocean.

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Question 6

6 marks

(a) A marine researcher needs to determine the mass of a seawater sample. If the sample has a volume of \(8.0\text{ m}^{3}\) and a density of \(1025\text{ kg m}^{-3}\), calculate the mass of the sample and state the formula used.
(b) Describe how the formation of a thermocline and a halocline leads to the development of distinct layers within the ocean.
(c) Explain why the floating of ice on the ocean surface is important for the survival of marine organisms in polar regions, with reference to its role as a thermal insulator.

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