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AS and A Level Physics Original material Cambridge University Press 2010 1

7 Worksheet (AS)

Data needed to answer questions can be found in the Data, formulae and relationships sheet.

1 Smoke particles suspended in air inside a sealed container are illuminated by a strong source of

light and observed with a microscope. A smoke particle is seen to be in random motion.

What is the reason for this? [1]

A The smoke particle absorbs energy from the light source.

B The smoke particle collides with air molecules.

C The smoke particle collides with other smoke particles.

D There are convection currents in the air.

2 Liquid X has a density of 1400 kg m3and liquid Y has a density of 1600 kg m

3.

At what depth in each liquid is the pressure in liquid X equal to the pressure in liquid Y? [1]

Depth in liquid X / m Depth in liquid Y / m

A 14 16B 15 15

C 16 14

D 18 16

3 Why does the pressure of a gas increase when the volume decreases at constant temperature? [1]

A The gas molecules hit each other more often.

B The gas molecules hit the wall of the container at higher speeds.

C The gas molecules hit the wall of the container more often.

D There are more gas molecules present to hit the wall of the container.

4 Which statement is true about water molecules at 70 C? [1]

A There are forces between the molecules and no molecules have enough energy

to escape the liquid.

B There are forces between the molecules and some molecules have enough energy

to escape the liquid.

C There are no forces between the molecules and no molecules have enough energy

to escape the liquid.

D There are no forces between the molecules and some molecules have enough energy

to escape the liquid.

5 Which row correctly compares the ordering and the separation of molecules in solids,

liquids and gases? [1]

Ordering of molecules Separation of molecules

A molecules in a liquid have no ordersolid and gas molecules have about

the same separation

Bmolecules in a solid are more ordered

than in liquids

solid and liquid molecules have about

the same separation

Cmolecules in a solid are more ordered

than in liquids

liquid and gas molecules have about

the same separation

D molecules in a gas have no orderliquid and gas molecules have about

the same separation

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7 Worksheet (AS)

AS and A Level Physics Original material Cambridge University Press 2010 2

6 Describe the arrangement of atoms, the forces between the atoms and the motion of the

atoms in:

a a solid [3]

b a liquid [3]

c a gas. [3]

7 A small amount of gas is trapped inside a container. Describe the motion of the gas atomsas the temperature of the gas within the container is increased. [3]

8 State one difference and one similarity between the boiling and evaporation of water. [2]

9 A person of weight 820 N stands on one leg. The area of the foot in contact with the floor is

1.4 102m

2.

a Calculate the pressure exerted by the foot on the ground. [2]

b Explain what would happen to the pressure exerted on the floor if the person stands on

tiptoe on one leg. [1]

10 A bicycle of mass 35 kg is resting on its two tyres on flat ground. The pressure at the base

of each tyre is 1.5 105Pa. Calculate the area of each tyre in contact with the ground.

You may assume that each tyre supports half the weight of the bicycle. [4]

11 The diagram shows a sealed container filled with air and

attached to a manometer. The liquid in the manometer has

a density of 1200 kg m3

.

Atmospheric pressure is 1.02 105Pa.

a Calculate the pressure of the air inside the

sealed container. [3]

b Using the kinetic model, explain why the

pressure of the air in the container rises whenthe temperature increases. [3]

12 Copper has density 8930 kg m3and zinc has density 7130 kg m

3. Brass is an alloy or

mixture of copper and zinc which contains 75% copper and 25% zinc by volume.

Assuming that the total volume of the alloy is the sum of the volumes of the copper

and zinc used, determine:

a the mass of copper and zinc in a sample of brass of volume 1.0 m3 [2]

b the density of brass. [2]

Total:36

Score: %

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