edexcel gcse additinal science p2 final exam 12_13

ADDITIONAL SCIENCE – PHYSICS

FINAL EXAM – P2

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FORMULAE You may find theses formulae useful

charge = current × time Q = I × t

potential difference = current × resistance V = I × R

electrical power = current × potential difference P = I × V

energy transferred = current × potential difference × time E = I × V × t

force = mass × acceleration F = m × a

weight = mass × gravitational field strength W = m × g

momentum = mass × velocity p = m × v

work done = force × distance moved in the direction of the force E = F × d

GPE = m × g × h

Do not forget to include units in all your answers.

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FINAL EXAM – P2

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FINAL EXAM – P2 1 Turn over

Surname

Name

AMERICAN ACADEMY LARNACA

YEAR 5 FINAL EXAM

Additional Science − Physics

Unit 2: Physics for Your Future Higher Tier

Wednesday 14 January 2013 Time: 1 hour

You must have: Calculator, ruler

Total Marks

Instructions • Use black ink or ball point pen. • Fill in the boxes at the top of this page with your Surname and Name. • Answer all questions. • Answer the questions in the spaces provided − there may be more space than you need. Information • The total mark for this paper is 60. • The marks for each question are shown in brackets − use this as a guide as to how much time to spend on each question. • Questions labelled with an asterisk (*) are ones where the quality

of your written communication will be assessed − you should take particular care with your spelling, punctuation and grammar,

as well as the clarity of expression, on these questions. Advice • Read each question carefully before you start to answer it. • Keep an eye on the time. • Try to answer every question. • Check your answers if you have time at the end.



_______________________________________________________________________________________ 1. (a) Below you can see the structure of a neutral atom.

Complete the names of the sub-atomic particles. [3 marks]

(b) Industrial smokestacks use static electricity to remove smoke and dust particles from their

waste gases. The picture below shows how such smokestacks work.

(i) Put a cross ( ) in the box next to the correct answer.

[1 mark] Smoke particles become negatively charged because

A they gain electrons

B they gain neutrons

C they gain protons

D they gain atoms

: ……………………………………………

name: ……………………………………………

: ……………………………………………

smokestack charged plates attract smoke particles

negative grid gives smoke particles a negative charge

waste gases with smoke particles

waste gases without smoke particles

smokestack wall

smoke collector



(ii) The plates are charged to attract the smoke particles.

Explain what charge should the plates have. [1 mark]

……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… (c) Static electricity presents a danger for refuelling planes.

Charge can pass to the plane as fuel flows through the pipes. (i) Put a cross ( ) in the box next to the correct answer.

[1 mark] This type of charging is called charging by

A flowing

B friction

C induction

D ionization

(ii) x “ ” .

[2 marks] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………

[Total for Question 1 = 8 marks] _______________________________________________________________________________________



_______________________________________________________________________________________ 2. (a) Radioactive decay is one type of nuclear reactions. (i) Connect each type of radioactive decay on the left to its correct property on the right.

[2 marks]

alpha • • high frequency electromagnetic radiation

beta • • highly ionizing massive particle

gamma • • light particle with a negative charge

(ii) Put a cross ( ) in the box next to the correct answer.

[1 mark] Which type or types of radiation will penetrate thick aluminium?

A Only alpha and beta

B Only beta and gamma

C Only gamma

D All three types

(b) Fusion is another types of nuclear reactions. (i) Put a cross ( ) in the box next to the correct answer.

[1 mark] Which is not a necessary condition for two nuclei to fuse?

A High kinetic energy

B High pressure

C High proton number

D High temperature

(ii) Explain why special conditions are necessary for nuclear fusion to take place.

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………



(c) The picture below shows the main structures of a nuclear reactor.

Controlled chain reactions make it possible to use a nuclear reactor to produce electricity.

Controlled chain reactions, like the one schematically shown below, make it possible to use

a nuclear reactor to produce electricity.

Explain what is meant by a controlled chain reaction.

Describe how chain reactions are controlled in a nuclear reactor. [3 marks]

……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………


Uranium fuel rods

moderator

Boron control rods



_______________________________________________________________________________________ 3. (a) A refrigerator model uses a thermistor in series with a variable resistor and a cooling unit.

The graph below shows how the resistance of the thermistor changes with temperature.

The cooling motor starts to work when the current in the thermistor is higher than 0.01 A.

The voltage across the thermistor is 200 V. (i) Use the graph to find at which temperature the cooling motor starts to work.

Show your working. [3 marks]

T ………………………… °C (ii) The owner increases the resistance of the variable resistor.

Explain the effect that this will have on the temperature of the refrigerator. [2 marks]

……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………

0

10

20

30

40

50

-30 -20 -10 0 10 20

Resistance (kΩ)

Temperature (°C)

mains

cooling unit thermistor

refrigerator

variable resistor



(b) A computer requires an adaptor to be connected to the mains.

(i) Put a cross ( ) in the box next to the correct answer.

[1 mark] One of the functions of the adaptor is to transform the current as shown below.

Which component would be suitable for this transformation?

A A diode

B An insulator

C An LDR

D An Ohmic conductor

(ii) A computer uses a voltage of 19 V and a current of 4.7 A.

Calculate the electrical energy the computer uses in 4 hours. [2 marks]

………………………… J (iii) Explain why a computer heats up when it is working.

[2 marks] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………


current

time

current

time



_______________________________________________________________________________________ 4. Submarines need to balance forces in all directions to control their movement in water. (a) The picture below shows a submarine moving underwater at constant velocity.

The dot on the right represents the centre of mass of the submarine. Complete the free body force diagram and name the missing forces.

[2 marks]

(b) (i) Thrust is produced by the submarine pushing the water backwards.

Put a cross ( ) in the box next to the correct answer. [1 mark]

The force on the water is

A equal to the Thrust

B equal to the Upthrust

C larger than the Thrust

D larger than the Upthrust

(ii) The submarine moves at constant velocity for 2 km.

Calculate the work done by thrust. [2 marks]

W ………………………… J (iii) Explain whether you think Upthrust is a vector or a scalar quantity.

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………

Upthrust = 80 × 106 N

Thrust = 20 × 106 N



(c) (i) Show that the mass of the submarine is 8 000 tonnes.

1 tonne = 1 000 kg. g = 10 N/kg.

[1 mark] The thrust increases to 24 × 106 N.

All other forces, including resistive ones, remain unchanged. (ii) Calculate the acceleration of the submarine at that instant.

Include the unit. [3 marks]

A ………………………… ………………




_______________________________________________________________________________________ 5. (a) The picture below shows a car accident demonstrating crumple zones.

(i) The driver in the picture claimed that he pressed the brakes but the car did not stop

over the usual distance. State one factor, besides speed, that could increase the braking distance of the car.

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… (ii) The car has a mass of 880 kg.

It was moving at 8 m/s before the crash. Show that the momentum of the car before collision was about 7 000 kg m / s.

[1 mark] (iii) The force on the car during the crash was 8 500 N.

Calculate the time that it took the car to come to a complete stop. [2 marks]

T ………………………… (iv) Explain how the crumple zones help to protect the driver during the crash.

[2 marks] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………



* (b) The Empire Building is 380 m high.

An urban myth states that a 3 gram penny dropped from the Empire Building can kill if it hits a person. The actual speed of the penny will never be greater than 20 m/s. T bj 0 ’ . Use energy conservation and do the necessary calculations to show that a penny dropped from a height of 20 m will have a speed of 20 m/s. Explain why the penny will not develop a higher speed even if dropped from larger height. Take g = 10 m s−2.

[6 marks] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………




_______________________________________________________________________________________ 6. Gamma rays are extensively used in medicine and industry.

They are also part of background radiation. (a) Name a source of background radiation.

[1 mark] ……………………………………………………………………………………………………………………………………………………… (b) Cobalt-60 is a common source of gamma radiation used in medicine and industry. (i) The symbol of this radioactive isotope of Cobalt is

0

The stable isotope of Cobalt has one neutron less. Complete the symbol below for the stable Cobalt isotope.

[1 mark]

The graph below shows the activity of Co-60 over a period of years.

(ii) Use the graph to find the half-life of Co-60.

[1 mark] Half-life = …………………………………………………………………………………………………………………………

0

2

4

6

8

10

12

0 1 2 3 4 5 6 7

Activity / × 109 Bq

Times / years

Co ………

………



(iii) Explain why the activity of Co-60 decreases with time.

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… (iv) A company uses Co-60 to sterilize fruits during packaging.

The source should be replaced when the activity of the source drops to 1/8 of the

initial activity of the source. Calculate the time period after which the source should be replaced.

[2 marks]

T …………………………

fruit packages

gamma source

gamma rays


FINAL EXAM – P2 14

* (c) IMRT is a new technique that uses gamma rays to destroy cancer cells.

The picture below shows how this technique is used against cancer in the throat. Gamma rays are directed onto the patient from various angles.

Describe the effect of gamma rays on living tissue.

Explain why gamma rays are used instead of alpha or beta rays. Explain why using multiple beams is safer for the patient.

[6 marks] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………


END TOTAL FOR PAPER = 60 MARKS

FINAL EXAM – ADDITIONAL SCIENCE − PHYSICS – MARK SCHEME

P2 – MARK SCHEME 15

MARK SCHEME p. 2 & 3 1. (a)

All 3 correct [3 marks]

If protons mixed up with neutrons [2 marks] (b) (i) A [1 mark] (ii) Positive because opposite charges attract (or similar) [1 mark] (b) (i) B [1 mark] (ii) Connecting plane Earth with a metal / conductor (or similar) [1 mark]

Charge /Electrons etc. escape to Earth / Prevents charge accumulation etc. [1 mark] p. 4 & 5 2. (a) (i)

alpha • • high frequency electromagnetic radiation

beta • • highly ionizing massive particle

gamma • • light particle with a negative charge

All correct [2 marks]; 1 correct [1 mark] (ii) C [1 mark] (b) (i) C [1 mark] (ii) Nuclei repel each other (because of the same charge) (or similar) [1 mark] (c) Any three from [3 marks]

One nucleus breaks up / undergoes fission at every step (or similar) Only one neutron absorbed by a Uranium nucleus at every step (or similar) Two neutrons not absorbed by other Uranium nuclei Boron / Control rods absorb extra neutrons Lowered if temperature increases, Raised if temperature decreases

name: neutron

name: proton

name: electron



p. 6 & 7 3. (a) (i) V = I R => 200 = 0.01 × R Formula & Substitution [1 mark]

R = 200 / 0.01 = 20 000 Ω 0 Ω Rearrangement & Answer [2 marks] its Temperature = −16 °C (allow ecf from previous step) [1 mark]

(ii) The temperature increases [1 mark]

& Any one from [1 mark] Total resistance increases Current become smaller Temperature must increase to make {resistance small / current large } again

(b) (i) A [1 mark] (ii) 4.7 hrs = 4 × 3600 = 14 400 sec Conversion [1 mark]

E = I V t = 4.7 × 19 × 14400 = 1 285 920 J = 1 300 000 J (allow ecf from time) [2 marks] its (iii) Any two from [2 marks]

Current causes heat / temperature increase Because electrons collide with (lattice) atoms (or similar) Atoms start vibrating faster

p. 8 & 9 4. (a)

Any 2 correct (name or arrow) [1 mark]

All 4 correct [2 marks] (b) (i) A [1 mark] (ii) W = F × d = 20 × 106 × 2000 Formula and substitution [1 mark]

W = 4 × 1010 J Answer [2 marks] its Vector because has direction / represented by arrow (or similar) [1 mark] (c) (i) W = m g => 80 × 106 = 10 m => m = 80 × 106 / 10 = 8 × 106 [1 mark] for working (ii) ΣF = (24 – 20) × 106 N [1 mark]

ΣF = m a => 4 × 106 = 8 × 106 × a Formula & Substitution [2 marks] its a = 0.5 m s−2 Answer & unit [3 marks] its

Upthrust = 80 × 106 N (given)

Thrust = 20 × 106 N (given)

Weight 2 cm (by eye)

Drag / Water resistance 0.5 cm (by eye)



p. 10 & 11 5. (a) (i) Any one from [1 mark]

Bad / Worn brakes (or similar) Wet / Slippery / Bad road (or similar)

(ii) p = m v = 880 × 8 = 7040 = 7000 kg m s−1 [1 mark] for working (iii) F = p / t => 8500 = 7040 / t Formula & Substitution [1 mark]

t = 7040 / 8500 = 0.83 = 0.8 sec Rearrangement & Answer [1 mark] (iv) Any one from [1 mark]

Time of crash increases Crumple zone absorbs part of (kinetic) energy & Force on driver smaller (or similar) [1 mark]

* (b) GPE = KE => m g h = ½ m v2 => g h = ½ v2

10 × 20 = ½ × 202 = 200 J (both LHS & RHS) Air resistance acting on penny As v increases Drag increases as well Until Drag = Weight => ΣF = 0 => a = 0 => v stays constant

Level Marks 1 1 – 2 Refers to other forces acting on the penny

Understands that ΣF is affected / decreased 2 3 − 4 Refers to Air resistance / Drag

Refers to how speed affects Drag Refers to ΣF = 0 / a = 0

3 5 − 6 Performs energy calculations Either as shown or starting from KE or from GPE



p. 12, 13 & 14 6. (a) Any one from [1 mark]

Cosmic radiation Radioactive elements in stones / buildings Radioactive elements / C-14 in food Nuclear power stations / Hospitals

(b) (i)

[1 mark] (ii) T1/2 = 5 yrs [1 mark] (iii) Any one from [1 mark]

Fewer nuclei undecayed as time goes by Activity is proportional to number of undecayed nuclei (or similar)

(iv) 1 1/8 => 3 T1/2 (or similar) [1 mark]

t = 3 × 5 = 15 yrs [2 marks] its

* (c) Gamma-rays = ionizing => cause mutation & cancer / kill cells Gamma more penetrating than alpha or beta Gamma less ionizing than alpha or beta => less dangerous for living tissue Multiple beams => minimum effect on healthy tissue & maximum effect on cancerous cells

Level Marks 1 1 – 2 Identifies danger from gamma rays

Identifies it is safer than alpha and beta 2 3 − 4 Relates danger to ionizing ability

Refers to mutation &/V cancer May refer to vague effect of multiple beams

3 5 − 6 Identifies that multiple beams affect healthy tissue less

edexcel gcse additinal science p2 final exam 12_13

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