UNIT 6: (Double Award) PHYSICS 2 HIGHER TIER SAMPLE

GCSE SCIENCE (Double Award) Sample Assessment Materials 305

Candidate Name Centre Number Candidate Number

GCSE

SCIENCE (Double Award)

UNIT 6: (Double Award) PHYSICS 2

HIGHER TIER

SAMPLE ASSESSMENT MATERIALS

(1 hour 15 minutes)

For Examiner’s use only

Question Maximum Mark Mark Awarded

1. 15

2. 11

3. 9

4. 17

5. 8

Total 60

ADDITIONAL MATERIALS In addition to this paper you will require a calculator.

INSTRUCTIONS TO CANDIDATES Use black ink or black ball-point pen. Do not use gel pen. Do not use correction fluid. Write your name, centre number and candidate number in the spaces at the top of this page Answer all questions. Write your answers in the spaces provided in this booklet.

INFORMATION FOR CANDIDATES The number of marks is given in brackets at the end of each question or part-question. Question 3(a) is a quality of extended response (QER) question where your writing skills will be assessed.

Equations

distance speed  time change in velocity v acceleration [or deceleration]  a  time t acceleration = gradient of a velocity-time graph

distance travelled = area under a velocity-time graph

resultant force = mass  acceleration F = ma

weight = mass  gravitational field strength W = mg

work = force  distance W = Fd

mass x velocity2 KE =1 mv2 kinetic energy = 2 2 change in potential energy = mass  gravitational field strength PE = mgh  change in height force = spring constant  extension F = kx work done in stretching = area under a force-extension graph W =1 Fx 2

SI multipliers

Prefix Multiplier p 1  10-12 n 1  10-9  1  10-6 m 1  10-3

Prefix Multiplier k 1  103 M 1  106 G 1  109 T 1  1012

Answer all questions

1. Read the information below then answer the questions that follow.

Speed is a critical factor in all road traffic accidents (RTA). Driving is unpredictable and if something unexpected happens on the road ahead – such as a child stepping out from between parked cars – it is a driver’s speed that will determine whether they can stop in time, and if they can’t stop - the size of the impact force.

Hence reducing and managing traffic speeds is crucial to road safety. It has been estimated that for every 1 mph reduction in mean speeds, RTA rates fall by an average of 5%. Breaking the speed limit or travelling too fast for the road conditions is recorded as a contributory factor in more than one in four (28%) serious RTAs in the UK. Research has found that British drivers who regularly exceed the speed limit are nearly twice as likely to have been involved in a RTA.

Stopping distances include the distance travelled while the driver notices a hazard and applies the brakes (thinking distance), and while the vehicle comes to a full stop from its initial speed (braking distance). Typical minimum stopping distances for cars are shown below.

Source: Department for Transport, 2007

Technology such as anti-lock brakes and stability control are designed to enable greater control over the vehicle, not shorten stopping distances. There may be a very small reduction in braking distance with modern technology, but not enough to significantly affect overall stopping distance. Technology such as air bags is designed to reduce the harm to passengers in the event of a RTA. Whatever technology a vehicle has, the basic fact remains that the bigger the speed, the longer the stopping distance, and the less chance of stopping in time in an emergency.

Adapted from: http://www.brake.org.uk/news/15-facts-a-resources/facts/1255-speed

(a) Read the following statements and tick () the boxes next to the correct statements. [2]

A speed limit of 30 mph indicates that it is always safe to travel at 30 mph in that area

Cars always have a braking distance of 24 m at 40 mph

Travelling twice as fast always doubles the thinking distance

The typical minimum overall stopping distance at 50 mph is 53 m

(b) Explain in practice why actual stopping distances may differ from the minimum distances shown on the diagram. [3]

…………………………………………………………………………………………………..

(d) Using the patterns shown in the data, calculate the overall stopping distance at 80 mph. [3]

stopping distance = …………………. m

(e) (i) The text suggests that air bags reduce the harm to passengers in the event of an accident. Explain how they do this. [2]

………………………………………………………………………………………….

(ii) Name another safety feature of cars other than air bags. [1]

………………………………………………………………………………………….

(f) The text states that: “It has been estimated that for every 1 mph reduction in mean speed, crash rates fall by an average of 5%.” Suggest measures that are taken to encourage people to drive more slowly. [2]

…………………………………………………………………………………………………..

2. A class of students used 50, 6-sided dice to model radioactive decay. Each of 8 groups gathered data which were added together to give the class results shown in the table below.

(a) Describe the method each group used to collect data. [3]

…………………………………………………………………………………………………..

The table shows the class results.

Number of rolls Number of dice remaining 0 400 1 335 2 281 3 230 4 245 5 163 6 135 7 108 8 92

(b) Plot a graph of the data on the grid below. [3]

Number of dice remaining

Number of rolls

(c) (i) The experiment is modelling the process of radioactive decay. Which important quantity relating to radioactive decay can be estimated from the graph? [1]

………………………………………………………………………………………….

(ii) Use your graph to estimate this quantity. [2]

………………………………………………………………………………………….

(d) Explain how the results would be different if 12 sided dice were used instead. [2]

…………………………………………………………………………………………………..

3. Zeta Puppis is a main sequence blue star in the constellation of Puppis, also known by the traditional name Naos. It is the 62nd brightest star visible from the Earth and is o approximately 1 090 light years away. It has a surface temperature of 42 400 C and mass 22.5 times that of the Sun. This means that it will use up its fuel much more quickly than the Sun and move away from the main sequence.

(a) Describe and explain the remaining observable stages in the life cycle of the star Zeta Puppis. [6 QER]

…………………………………………………………………………………………………..

(b) Describe the formation of our solar system. [3]

…………………………………………………………………………………………………..

4. A bottle rocket contains water and air which has been pressurised. When launched the air pushes water out of the bottle.

A rocket of total mass 0.5 kg is launched vertically. (Gravitational field strength = 10 N/kg.)

(a) (i) State Newton’s third law. [2]

………………………………………………………………………………………….

(ii) Explain how Newton’s third law applies to the rocket. [2]

………………………………………………………………………………………….

(b) At 1 m above the ground all the water has left the rocket. At this point the rocket has 5 J of potential energy and a velocity of 22 m/s. Use equations from page 2 to calculate the maximum height that could be reached by the rocket. Show your workings clearly. [5]

height = ………….. m

…………………………………………………………………………………………………..

2 (d) The initial acceleration of the rocket is 4 m/s .

(i) Use Newton’s second law to calculate the initial resultant force acting on the rocket. [3]

initial resultant force = ………………… N

(ii) Calculate the size of the initial thrust force. [2]

initial thrust force = ……………. N

(iii) A student suggests that the resultant force increases as the rocket gains height. Give a reason why. [1]

………………………………………………………………………………………….

5. Read the information below then answer the questions that follow:

Dimitri Mendeleev predicted the existence of an element with atomic number 43 in 1871. Element 43, now known as technetium, was actually discovered in 1937. Technetium is the element in the periodic table with the lowest atomic number which has no stable isotopes. Technetium-99 is one isotope of technetium which has a half- life of 2.11  105 years. It decays by ‘soft’ beta decay – the electrons emitted are low energy electrons. Technetium-99m is a form of technetium which is used as a radioactive tracer; it decays to technetium-99 by gamma emission with a half-life of 6 hours. A patient is injected with the isotope and when a technetium-99m nucleus decays it emits gamma radiation which is easily detected outside the body. This technique is used to tell us about the function of parts of the body such as the heart, liver and lungs.

(a) (i) State the number of protons in a nucleus of technetium. [1]

………………………………………………………………………………………….

(ii) Two types of radioactive decay are mentioned in the text. Name the other type of radioactive decay and state what it is. [2]

………………………………………………………………………………………….

(iii) The initial activity of a sample of technetium-99m is 5  104 Bq. Calculate the activity remaining after 2.5 days. [3]

activity = ……………….. Bq

(b) The isotope of technetium with the longest half-life is technetium-98. It has a half-life of 4.2 million years. In 1952 technetium-98 was detected in red giant stars [which are billions of years old]. Explain how the discovery of technetium-98 in these stars added support to the theory that heavier elements are produced within stars. [2]

…………………………………………………………………………………………………..

UNIT 6: (Double Award) PHYSICS 2 HIGHER TIER

MARK SCHEME

GENERAL INSTRUCTIONS

Recording of marks

Examiners must mark in red ink.

One tick must equate to one mark (apart from the questions where a level of response mark scheme is applied).

Question totals should be written in the box at the end of the question.

Question totals should be entered onto the grid on the front cover and these should be added to give the script total for each candidate.

Marking rules

All work should be seen to have been marked.

Marking schemes will indicate when explicit working is deemed to be a necessary part of a correct answer.

Crossed out responses not replaced should be marked.

Credit will be given for correct and relevant alternative responses which are not recorded in the mark scheme.

Extended response question

A level of response mark scheme is used. Before applying the mark scheme please read through the whole answer from start to finish. Firstly, decide which level descriptor matches best with the candidate’s response: remember that you should be considering the overall quality of the response. Then decide which mark to award within the level. Award the higher mark in the level if there is a good match with both the content statements and the communication statements.

Marking abbreviations

The following may be used in marking schemes or in the marking of scripts to indicate reasons for the marks awarded. cao = correct answer only ecf = error carried forward bod = benefit of doubt

Marks Available Question Marking details AO1 AO2 AO3 Total Maths Prac rd th 1 (a) 3 and 4 boxes only ticked (2) -1 for additional boxes ticked 2 2 2 (b) Thinking distance is increased by factors like tiredness and alcohol (1)

Braking distance is increased by wet roads / poor brakes / heavy

loads (1) 3 3 Hence the distances given only correspond to best possible conditions (1) (c) As speed doubles braking distance increases (1) By a factor of 4 (1) 2 2 (d) 24 [m] (1) 1 96 [m] (1) 1

Substitution: 24 +96 = 120 [m] (1) ecf 1 3 3

(e) (i) Air bags increase the time taken to stop / increase the distance the passenger travels whilst stopping (1) 2 2 reducing the force acting on passenger (1) (ii) Any (1) from:  Crumple zone

 Side impact protection bars 1 1  Seat belt (f) Any 2 (1) from:  Use of speed bumps / speed cameras

 Speed limits 2 2  Public awareness campaigns

Question 1 total 2 6 7 15 5 0

Marks Available Question Marking details AO1 AO2 AO3 Total Maths Prac 2 (a) Dice are rolled and all those with a certain number facing

upwards are removed (1)

Number of dice remaining are recorded (1) 3 3 3 Remaining dice re-rolled a number of times (1)

(b) Suitable scales (i.e. intervals of 50 on the y-axis and intervals of 1 on the x-axis) (1) All 9 points correctly plotted within ± ½ small square division (1) Smooth curve of best fit within ± ½ small square division of all points ignoring anomaly (1) Don't accept thick, double, whispy 3 3 3 3 lines

(ii) Correct method clear from graph (1) Answer consistent with graph to 1 d.p.(1) 2 2 2

(d) Longer half-life / less dice decay each time (1) Since probability of decay is lower (1) 2 2 2

Question 2 total 4 5 2 11 3 11

Marks Available Question Marking details AO1 AO2 AO3 Total Maths Prac 3 (a) Indicative content: Initially the star is fusing hydrogen, it is stable as the forces of gravitation and radiation pressure are equal and opposite. Once

hydrogen is largely exhausted helium fuses, the radiation pressure

is bigger than the inward gravity forces and the star's outer layers

expand and cool, the star becomes a supergiant. Fusion of

increasingly heavier elements occurs in layers around the core.

Once fusion stops, the star's core rapidly collapses and then

explodes in a supernova, scattering material from the outer layers

of the star into space. The core then contracts and cools, becoming

either a neutron star or a black hole.

5 – 6 marks: Clear description of each stage in the life cycle with

reference to role of fusion and the forces acting. 6 6 There is a sustained line of reasoning which is coherent, relevant,

substantiated and logically structured. The candidate uses

appropriate scientific terminology and accurate spelling,

punctuation and grammar.

3 – 4 marks: Each stage in the life cycle is named with some

references to fusion / forces at each stage.

There is a line of reasoning which is partially coherent, largely

relevant, supported by some evidence and with some structure.

The candidate uses mainly appropriate scientific terminology and

some accurate spelling, punctuation and grammar.

1-2 marks: Name of each stage in the life is given. Some stages

named / detail given.

There is a basic line of reasoning which is not coherent, largely

irrelevant, supported by limited evidence and with very little

structure. The candidate uses limited scientific terminology and

inaccuracies in spelling, punctuation and grammar.

0 marks: No attempt made or no response worthy of credit.

Marks Available Question Marking details AO1 AO2 AO3 Total Maths Prac 3 (b) Cloud of dust and gas (1) and heavy elements ejected by supernovae (1) collapse under gravitational attraction (1) 3 3

Question 3 total 9 0 0 9 0 0

Marks Available Question Marking details AO1 AO2 AO3 Total Maths Prac 4 (a) (i) If a body A exerts a force on body B (1)

then body B exerts an equal and opposite force on body A (1) 2 2 Accept: Every action has an equal and opposite reaction (1)

which act on different bodies (1) (ii) Rocket / air exerts a downwards force on the water (1) so water exerts an upward force on the rocket (1) 2 2

(b) Substitution: KE = ½  0.5  222 (1) 1 KE = 121 [J] (1) 1 PE = total energy = 126 [J] (1) 1 Substitution: 0.5  10  h = 126 (1) 1 h = 25.2 [m] (1) 1 5 5

(c) Not all KE transferred to GPE (1) Some lost as work is done against air resistance (1) 2 2 (d) (i) Use of F = ma (1) 1

F = 0.5  4 (1) 1 3 3 F = 2.0 [N] (1) 1 (ii) 2.0 + 5.0 (ecf) (1)

Thrust = 7.0 [N] (1) 2 2 2 (iii) Rocket mass decreases reducing weight as water is ejected 1 1

Question 4 total 6 10 1 17 10 0

Marks Available Question Marking details AO1 AO2 AO3 Total Maths Prac 5 (a) (i) 43 1 1 (ii) Alpha decay (1) Helium nucleus (1) accept 2p + 2n 2 2 (iii) 2.5 days = 60 hours = 10 half-lives (1) 5 x 104 Activity remaining = (1) 210 = 49 [Bq] (1) 3 3 3 (b) Any technetium-98 initially present in the star would have all decayed (1) so it must have been made later (1) 2 2

Question 5 total 3 3 2 8 3 0

HIGHER TIER

SUMMARY OF MARKS ALLOCATED TO ASSESSMENT OBJECTIVES

Question AO1 AO2 AO3 TOTAL MARK MATHS PRAC

1 2 6 7 15 5 0

2 4 5 2 11 3 11

3 9 0 0 9 0 0

4 6 10 1 17 10 0

5 3 3 2 8 3 0

TOTAL 24 24 12 60 21 11