GCSE Physics Revision: 8) Separate Only Sections 1 to 5 V1

GCSE Physics Revision: 8) Separate only sections 1 to 5 V1

Q1.

You wash and dry your hair, then comb it with a plastic comb. As you move the comb away from your head some hairs are attracted to the comb.

(a) What has happened to the comb to make it attract the hairs?

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______

(1)

(b) If the comb is now held above some small pieces of dry tissue paper what is likely tohappen?

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______

(1)

(c) If you rub your hands all over the comb it will no longer attract your hair.
Explain why.

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______

(2)

(Total 4 marks)

Q2.

The figure below shows a balloon filled with helium gas.

(a)Describe the movement of the particles of helium gas inside the balloon.

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(2)

(b)What name is given to the total kinetic energy and potential energy of all the particles of helium gas in the balloon?

(1)

(c)Write down the equation which links density, mass and volume.

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(1)

(d)The helium in the balloon has a mass of 0.00254 kg.

The balloon has a volume of 0.0141 m3.

Calculate the density of helium. Choose the correct unit from the box.

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Density = ______Unit ______

(3)

(Total 7 marks)

Q3.

(a) Fine powders poured through a pipe can become charged. The diagram shows the apparatus used by a student to investigate this effect.

The student poured 75 cm3 of polystyrene beads down the pipe. The beads fell into a metal can and the charge on them was measured directly using a coulombmeter.

The student repeated this twice more, but each time used 75 cm3 of beads of a different size.

(i)When they fell through the pipe, the polystyrene beads became negatively charged.

Explain how this happened.

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(3)

(ii)Give one control variable in the student's investigation.

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(1)

(b) The results obtained by the student are shown in the table.

(1 000 000 microcoulombs = 1 coulomb)

(i)Describe the connection between the size of the polystyrene beads and the total charge on the beads.

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______

(1)

(ii)Explain how these results might be different if the student had used a shorter pipe.

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(2)

(c) In industry, powders are often pumped through pipes. If the static charge caused a spark, the powder could ignite and cause an explosion.

(i)Is an explosion more likely to happen when pumping very fine powders or when pumping powders that consist of much larger particles?

______

Give a reason for your answer.

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______

(1)

(ii)Suggest one way that the risk of an explosion could be reduced.

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(1)

(d) The table gives the minimum ignition energy (MIE) value for a number of fine powders.
The MIE is the minimum amount of energy required to cause a fine powder to ignite.

The MIE values for different substances are all measured in the same way and under the same conditions of pressure and temperature.

Why is this important?

______

______

(1)

(Total 10 marks)

Q4.

(a) A teacher used a Geiger-Műller (GM) tube and counter to measure the background radiation in her laboratory.

The teacher reset the counter to zero, waited one minute and then took the count reading. The teacher repeated the procedure two more times.

(i)Background radiation can be either from natural sources or from man-made sources.

Name one man-made source of background radiation.

______

(1)

(ii)The three readings taken by the teacher are given in the table.

The readings given in the table are correct.

Why are the readings different?

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(1)

(b) Some scientists say they have found evidence to show that people living in areas of high natural background radiation are less likely to develop cancer than people living in similar areas with lower background radiation.

The evidence these scientists found does not definitely mean that the level of background radiation determines whether a person will develop cancer.

Suggest a reason why.

______

______

(1)

(c) An atom of the isotope radon-222 emits an alpha particle and decays into an atom of polonium.

An alpha particle is the same as a helium nucleus. The symbol below represents an alpha particle.

(i)How many protons and how many neutrons are there in an alpha particle?

Number of protons = ______

Number of neutrons = ______

(2)

(ii)The decay of radon-222 can be represented by the equation below.

Complete the equation by writing the correct number in each of the two boxes.

(2)

(d) The graph shows how, in a sample of air, the number of radon-222 nuclei changes with time.

Time in days

Use the graph to find the half-life of radon-222.

Show clearly on the graph how you obtain your answer.

Half-life = ______days

(2)

(Total 9 marks)

Q5.

A drum is hit by a beater attached to a drumstick lever. The drumstick lever is attached to a foot-pedal by a chain, as shown in the Figure 1.

Figure 1

(a) When the toe is pushed down the force creates a moment on the foot-pedal.

(i) State what is meant by the moment of a force.

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______

(1)

(ii) The foot-pedal is pushed halfway down and held stationary. The toe and the chain both exert a force on the foot-pedal.

Compare the sizes and directions of the moments caused by the force of the toe and the force of the chain on the foot-pedal.

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______

(1)

(iii) The drummer’s toe pushes with a 1.5 N force on the foot-pedal.

The perpendicular distance from the pivot to the force is 0.12 m.

The perpendicular distance from the pivot to the chain is 0.20 m.

Calculate the force of the chain acting on the foot-pedal.

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Force = ______N

(3)

(b) The foot-pedal is pushed with different forces to make the beater move at different speeds.

The higher the speed at which the beater hits the drum, the louder the sound the drum makes.

Figure 2 shows how the length of the drumstick lever affects the speed of the beater for three different forces.

Figure 2

The drummer needs to be able to sometimes play the drum quietly and sometimes loudly.

How does the length of the drumstick lever affect the variation in loudness of the sound from the drum when applying:

a force of 3 N? ______

______

a range of forces from 3 N to 9 N? ______

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(2)

(Total 7 marks)

Q6.

Nuclear fission and nuclear fusion are two processes that release energy.

(a) (i)Use the correct answer from the box to complete each sentence.

Nuclear fission takes place within a ______.

Nuclear fusion takes place within a ______.

(2)

(ii)State one way in which the process of nuclear fusion differs from the process of nuclear fission.

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______

(1)

(b) The following nuclear equation represents the fission of uranium-235 (U-235).

Chemical symbols:

Ba - barium

Kr - krypton

(i)Use the information in the equation to describe the process of nuclear fission.

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(4)

(ii)An isotope of barium is Ba-139.
Ba-139 decays by beta decay to lanthanum-139 (La-139).

Complete the nuclear equation that represents the decay of Ba-139 to La-139.

(3)

(Total 10 marks)

Q7.

The diagram shows a child on a playground swing.
The playground has a rubber safety surface.

(a) The child, with a mass of 35 kg, falls off the swing and hits the ground at a speed of 6m/s.

(i) Calculate the momentum of the child as it hits the ground.

Show clearly how you work out your answer and give the unit.

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Momentum = ______

(3)

(ii) After hitting the ground, the child slows down and stops in 0.25 s.
Calculate the force exerted by the ground on the child.

Show clearly how you work out your answer.

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Force = ______N

(2)

(b) The diagram shows the type of rubber tile used to cover the playground surface.

Explain how the rubber tiles reduce the risk of children being seriously injured when they fall off the playground equipment.

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(3)

(c) The ‘critical fall height’ is the height that a child can fall and not be expected to sustain a life-threatening head injury.
A new type of tile, made in a range of different thicknesses, was tested in a laboratory using test dummies and the ‘critical fall height’ measured. Only one test was completed on each tile.

The results are shown in the graph.

The ‘critical fall height’ for playground equipment varies from 0.5 m to 3.0 m.

Suggest two reasons why more tests are needed before this new type of tile can be used in a playground.

1. ______

______

2. ______

______

(2)

(d) Developments in technology allow manufacturers to make rubber tiles from scrap car tyres.

Suggest why this process may benefit the environment.

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______

(1)

(Total 11 marks)

Q8.

(a) Nuclear fission is used in nuclear power stations to generate electricity. Nuclear fusion happens naturally in stars.

(i)Explain briefly the difference between nuclear fission and nuclear fusion.

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(2)

(ii)What is released during both nuclear fission and nuclear fusion?

______

(1)

(b) Plutonium-239 is used as a fuel in some nuclear reactors.

(i)Name another substance used as a fuel in some nuclear reactors.

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(1)

(ii)There are many isotopes of plutonium.

What do the nuclei of different plutonium isotopes have in common?

______

(1)

(Total 5 marks)

Q9.

The diagram shows a water butt used to collect rainwater.

A tap allows water to be collected from the water butt in a watering can.

(a) If the tap was placed higher up on the water butt, what difference would it make to the rate of flow of water from the tap?

Explain your answer.

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(2)

(b) A hosepipe is now attached to the tap. The hosepipe takes water to where it is needed.

A gardener did an investigation to see how the rate of flow of water through a hosepipe, from a water butt, varies with the length of the hosepipe.

His results are shown in below table.

(i)What conclusions can you make based on the results in the table above?

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(2)

(ii)Suggest further readings that should be taken to improve the investigation.

Give reasons for your answers.

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(4)

(c) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.

You are provided with a water butt and lengths of hosepipe of different diameter.

Describe how you would investigate how the rate of flow of water through a hosepipe varies with the diameter of the hosepipe.

In your description you should include:

•any additional equipment that you would use

•any measurements you would make using the equipmentz

•any variables that need to be controlled and how this would be achieved.

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(6)

(Total 14 marks)

Q10.

The diagram shows a design for a crane. The crane is controlled by a computer.

The purpose of the motors and gears is to change the pulling force in the steel cable.
This is done so that the jib stays horizontal whatever the size of the load or the position of the load.

(a)Calculate the moment caused by the load in the position shown in the diagram.

Show clearly how you work out your answer and give the unit.

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Moment = ______

(3)

(b)Calculate the pulling force that is needed in the steel cable to keep the jib horizontal.

Show clearly how you work out your answer.

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Pulling force = ______N

(2)

(Total 5 marks)

Q11.

Food irradiation is a process that exposes food to radiation. Irradiation can be used to kill the bacteria that cause food poisoning or to slow down the ripening of fresh fruit and vegetables. Frozen foods and food inside packaging can also be irradiated.

(a)The table gives information about five radioactive isotopes.

Which of these radioactive isotopes would be most suitable for irradiating food?

______

Explain the reasons for your choice.

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(3)

(b)Many people think that food should not be irradiated. Consumer groups have said that they are worried about the nutritional value and safety of eating irradiated foods.

(i) Suggest one reason why some people may be concerned about the safety of eating irradiated food.

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(1)

(ii)Independent scientific committees in several countries, including Sweden, Canada and the UK, have concluded that it is safe to eat irradiated food.

These scientific committees need to be independent from government influence.

Suggest why.

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(1)

(iii) One group of scientists has compared the vitamin content of non-irradiated foods with irradiated foods.

The table below gives the data obtained for 1 kg of cooked chicken.

Considering only the data in the table, is it valid to conclude that irradiated food is less nutritional than non-irradiated food?

Explain your answer.

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(2)

(iv)In a restaurant, meals with ingredients that have been irradiated must be clearly identified on the menu.

It is important that people eating in a restaurant are given this information.

Suggest why.

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(1)

(c)The isotope caesium-137 decays by emitting beta radiation.
Caesium-137 has a half-life of 30 years.

(i) What is a beta particle, and from which part of an atom is a beta particle emitted?

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______

(1)

(ii)A sample containing caesium-137 has a count rate of 600 counts per minute.

Calculate how long it would take for the count rate from the sample to fall to 75 counts per minute.

Show clearly how you work out your answer.

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Time taken = ______years

(2)

(Total 11 marks)

Q12.

In some areas of the U.K. people are worried because their houses are built on rocks that release radon.

Read the information about radon.

• It is a gas.

• It is formed by the breakdown of radium.

• It emits alpha radiation.

• Each radon atom has 86 protons.

• Each radon atom has 136 neutrons.

Explain why it may be dangerous to live near rocks that release radon.

To gain full marks in this question you should write your ideas in good English. Put them into a sensible order and use the correct scientific words.

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(Total 3 marks)

GCSE Physics Revision: 8) Separate only sections 1 to 5 V1

Mark schemes

Q1.

(a)becomes (electrically) charged or description of electron movement

for 1 mark

1

(b) comb attracts paper

for 1 mark

1

(c) charge/electricity gone to Earth/body

for 1 mark each

2

[4]

Q2.

(a) range of speeds

1

moving in different directions

accept random motion

1

(b) internal energy

1

(c) density = mass / volume

1

(d) 0.00254 / 0.0141

1

0.18

1

accept 0.18 with no working shown for the 2 calculation marks

kg / m3

1

[7]

Q3.

(a) (i)friction between the beads and pipe

accept beads rub against the pipe

1

(cause) electrons to transfer

accept electrons are lost/gained

do not accept negatively charged atoms for electrons

3rd mark point only scores if 2nd mark scores

1

from the pipe

do not accept from the (negatively) charged pipe

or
to the beads

do not accept to the (positively) charged beads

accept negative charge transfer to the beads for 1 mark provided 2nd or 3rd marking point not awarded

mention of positive charge transfer negates last 2 marking points

1

(ii)volume of beads

accept (75)cm3

or
length of pipe

accept use the same pipe

or
speed the beads are poured

poured the same way is insufficient

or
angle of pipe

1

(b) (i)the larger the beads the less charge

do not accept inversely proportional

negative correlation is insufficient

1

(ii)(total) charge decrease

results would be lower/smaller would be insufficient

1

beads in contact with pipe (walls) for less time

accept less contact (between beads and pipe)

accept beads in pipe for less time

or
smaller surface area (to rub against)

accept less pipe to rub against

less friction is insufficient

1

(c) (i)(pumping very) fine powders

reason only scores if (very) fine powders given

greater charge (build up)

accept more static (electricity)

accept an answer that correctly relates back to the experimental data

or
higher pd/voltage
or
greater energy

accept larger surface area to volume (ratio)

1

(ii)idea of earthing (the pipe)

accept use metal pipes

do not accept use larger particles

1

(d) to compare (the relative risks)

fair test is insufficient

you can only have one

independent variable is insufficient

or
different conditions change the MIE value

accept different conditions change the results

do not accept avoid bias

1

[10]

Q4.

(a) (i) any one from:

•nuclear power (stations)

accept nuclear waste
accept coal power stations

•nuclear weapons (testing)

accept nuclear bombs / fallout

•nuclear accidents

accept named accident, eg Chernobyl or Fukushima

accept named medical procedure which involves a radioactive source
accept radiotherapy
accept X-rays
accept specific industrial examples that involve a radioactive source

nuclear activity / radiation is insufficient

smoke detectors is insufficient

1

(ii) (radioactive decay) is a random process

accept an answer in terms of background / radiation varies (from one point in time to another)

1

(b) any one from:

• (maybe) other factors involved

accept a named ‘sensible’ factor, eg smoking

• evidence may not be valid

accept not enough data

• may not have (a complete) understanding of the process (involved)

1

(c) (i) 2

1

2

1

(ii)218

correct order only

1

84

1

(d) 3.8 (days)

allow 1 mark for showing correct method using the graph provided no subsequent steps

correct answers obtained using numbers other than 800 and 400 gain2 marks provided the method is shown

2

[9]

Q5.

(a) (i) turning effect

accept force multiplied by perpendicular distance from the line of action of the force to the pivot

1

(ii) moments are equal (in size) and opposite (in direction)

both parts are required

allow clockwise moment = anticlockwise moment

1

(iii) 0.9 (N)

allow 2 marks for F = 0.18 ÷ 0.2 provided no subsequent steps