The Student Room Group

AQA Physics Unit 2 June 2017 Unofficial Mark Scheme

Radiation

Q. Name a common fuel used in nuclear reactors? (1 Mark)
- Uranium(235)

Q. What happens to a nucleus undergoing fission? (2 Mark)
- The nucleus absorbs a neutron, becoming unstable which causes it to break down into two smaller nuclei, while releasing lots of energy and 3 extra neutrons in random directions.

Q. Cosmic Rays %? (2 Mark)
-15%

Q. Why someone might take in larger dose of cosmic rays? (1 Mark)
-Higher exposure to cosmic rays e.g pilot

Q. Give an example of man made radiation? (1 Mark)
-Nuclear waste from nuclear weapons

Q. Why were the teachers 3 readings different? (2 Mark)
- Different sources emit different amounts of radiation, so even a small change in location would result in a change
- Result might be anomalous.

Rods and polarization:

Q. Explain using polarization what happens to the silk and nylon rod when rubbed? ( 3 mark )
-The nylon rod has a higher polarization than the silk, therefore its electrons are transferred to the silk (because of its weak polarization). The nylon rod becomes positive, due to loss of electrons and the silk becomes negative due to gain.

Q. What would happen if a pvc rod was used instead of nylon? (1 Mark)
-silk would become positively charged instead of negatively, due to a higher polarization.

Q. What will happen to the reading of the same charged rods?: ( 3 marks)
-Increase


Q. Give a reason:
-The two alike charges will repel, so the rod on the scale will get a greater downwards force, which will increase the reading


Braking Distances:

Q. Thinking distance definition: (1 Mark)
-Distance travelled during the driver’s reaction time

Q. Braking distance by lorry? (2 Marks)
-24m or 48 m

Q. Force exerted by the brakes? (2 marks)
- 15 000 newton

Q. Name one control variable for the test? (1 Mark)
-Mass or surface area of the car

Q. What else can the student measure which would show braking distance? (1 Mark)
- Height of the weight from the ground

Q. What do the results in figure x tell you about the relationship: (2 Marks)
-As the force increases, the distance increases.
20 N of force is required to initiate a brake.



Decay:

Q. The student concludes that the decay is beta, explain how the results from the figure support this? (2 Marks)
-Beta is moderately penetrating hence, the penetration decreases as aluminum gets thicker.

Q. How could the student test for alpha? (2 Marks)
Use longer distances to test for change over distance, since alpha particles don't travel far



Electricity:

Q. Voltage passing through finger to car: (2 Marks)
-9000V

Q. Wearing wool over any other clothing will give you a smaller charge, two reasons why not: (2 Marks)
Lack of range
Anomalous result



LEDs

Q.LED symbol: (1 Mark)
-Little skip button inside a circle. Two arrows pointing to the top right, placed above the circle.

Q. Energy transferred by the LED: (2 Marks)
-12J

Q. Why are LED's cheaper to run? (1Marks)
-Halogen and filament produce a lot of heat as waste energy

Q. Explain by using ions and electrons why temperature increases resistance: (3 Marks)
-An increase in temperature means an increase in energy. The more energy particles (ions) have the more they shake, which makes it difficult for electrons to pass by, therefore increasing the resistance

Stars:

Q. What happens at a supernova? ( 1 mark)
-The star is unstable, so explodes

Q. Why doesn’t sun undergoes a supernova stage?
-(??) 1 mark

Q. After exploding the star becomes a ? ( 1 mark)
-Supernova



Q. 6 marker:
-Gasses gather up in space and begin to cluster in to the centre of their own gravity. (nebula)
Heat from pressure results in an early star formation (protostar)
Fusion begins to occur from hydrogen atoms fusing into helium nuclei, which triggers the beginning of the main sequence star.
Here it is stable for millions of years, and fuses all of its hydrogen to generate heat and light
Once hydrogen runs out, the star begins to swell and its outer layers cool off, giving it a red colour (Red Giant)
Here it fuses atoms up to iron
Once it runs out of atoms to fuse, it dispenses its outer layer of gasses and rocks (planetary nebula) into space
White dwarf -----> black dwarf (cooling) = death of the star
(6 Marks)

Q. Scientific theory question, why accepts some but not others?: (2 Marks)
- Some theories proven wrong through investigation
Some theories seem more reasonable than others
Some theories may have insufficient evidence, or the evidence is unreliable and irrelevant



Momentum:

Q. Explain why, using idea of momentum, the cannon moves back when it shoots the ball? (3 Marks)
-Momentum before= momentum after. Conservation of momentum means that the cannon will move back with the same momentum as the ball, but in opposite direction (but different speed and weight)

Q. Cannon balls momentum after 0.05 seconds: (3 Marks)
- 1000 kg m/s
Original post by mn9011
Radiation

Q. Name a common fuel used in nuclear reactors? (1 Mark)
- Uranium(235)

Q. What happens to a nucleus undergoing fission? (2 Mark)
- The nucleus absorbs a neutron, becoming unstable which causes it to break down into two smaller nuclei, while releasing lots of energy and 3 extra neutrons in random directions.

Q. Cosmic Rays %? (2 Mark)
-15%

Q. Why someone might take in larger dose of cosmic rays? (1 Mark)
-Higher exposure to cosmic rays e.g pilot

Q. Give an example of man made radiation? (1 Mark)
-Nuclear waste from nuclear weapons

Q. Why were the teachers 3 readings different? (2 Mark)
- Different sources emit different amounts of radiation, so even a small change in location would result in a change
- Result might be anomalous.

Rods and polarization:

Q. Explain using polarization what happens to the silk and nylon rod when rubbed? ( 3 mark )
-The nylon rod has a higher polarization than the silk, therefore its electrons are transferred to the silk (because of its weak polarization). The nylon rod becomes positive, due to loss of electrons and the silk becomes negative due to gain.

Q. What would happen if a pvc rod was used instead of nylon? (1 Mark)
-silk would become positively charged instead of negatively, due to a higher polarization.

Q. What will happen to the reading of the same charged rods?: ( 3 marks)
-Increase


Q. Give a reason:
-The two alike charges will repel, so the rod on the scale will get a greater downwards force, which will increase the reading


Braking Distances:

Q. Thinking distance definition: (1 Mark)
-Distance travelled during the driver’s reaction time

Q. Braking distance by lorry? (2 Marks)
-24m or 48 m

Q. Force exerted by the brakes? (2 marks)
- 15 000 newton

Q. Name one control variable for the test? (1 Mark)
-Mass or surface area of the car

Q. What else can the student measure which would show braking distance? (1 Mark)
- Height of the weight from the ground

Q. What do the results in figure x tell you about the relationship: (2 Marks)
-As the force increases, the distance increases.
20 N of force is required to initiate a brake.



Decay:

Q. The student concludes that the decay is beta, explain how the results from the figure support this? (2 Marks)
-Beta is moderately penetrating hence, the penetration decreases as aluminum gets thicker.

Q. How could the student test for alpha? (2 Marks)
Use longer distances to test for change over distance, since alpha particles don't travel far



Electricity:

Q. Voltage passing through finger to car: (2 Marks)
-9000V

Q. Wearing wool over any other clothing will give you a smaller charge, two reasons why not: (2 Marks)
Lack of range
Anomalous result



LEDs

Q.LED symbol: (1 Mark)
-Little skip button inside a circle. Two arrows pointing to the top right, placed above the circle.

Q. Energy transferred by the LED: (2 Marks)
-12J

Q. Why are LED's cheaper to run? (1Marks)
-Halogen and filament produce a lot of heat as waste energy

Q. Explain by using ions and electrons why temperature increases resistance: (3 Marks)
-An increase in temperature means an increase in energy. The more energy particles (ions) have the more they shake, which makes it difficult for electrons to pass by, therefore increasing the resistance

Stars:

Q. What happens at a supernova? ( 1 mark)
-The star is unstable, so explodes

Q. Why doesn’t sun undergoes a supernova stage?
-(??) 1 mark

Q. After exploding the star becomes a ? ( 1 mark)
-Supernova



Q. 6 marker:
-Gasses gather up in space and begin to cluster in to the centre of their own gravity. (nebula)
Heat from pressure results in an early star formation (protostar)
Fusion begins to occur from hydrogen atoms fusing into helium nuclei, which triggers the beginning of the main sequence star.
Here it is stable for millions of years, and fuses all of its hydrogen to generate heat and light
Once hydrogen runs out, the star begins to swell and its outer layers cool off, giving it a red colour (Red Giant)
Here it fuses atoms up to iron
Once it runs out of atoms to fuse, it dispenses its outer layer of gasses and rocks (planetary nebula) into space
White dwarf -----> black dwarf (cooling) = death of the star
(6 Marks)

Q. Scientific theory question, why accepts some but not others?: (2 Marks)
- Some theories proven wrong through investigation
Some theories seem more reasonable than others
Some theories may have insufficient evidence, or the evidence is unreliable and irrelevant



Momentum:

Q. Explain why, using idea of momentum, the cannon moves back when it shoots the ball? (3 Marks)
-Momentum before= momentum after. Conservation of momentum means that the cannon will move back with the same momentum as the ball, but in opposite direction (but different speed and weight)

Q. Cannon balls momentum after 0.05 seconds: (3 Marks)
- 1000 kg m/s


Answer to Q. Why doesn’t sun undergoes a supernova stage? Only stars larger than our sun become a supernova

Answer to Q. After exploding the star becomes a ? ( 1 mark) Neutron Star
Reply 2
Original post by TODTEMPLE01
Answer to Q. Why doesn’t sun undergoes a supernova stage? Only stars larger than our sun become a supernova

Answer to Q. After exploding the star becomes a ? ( 1 mark) Neutron Star



What do u think an A* will be ?
Original post by mn9011
What do u think an A* will be ?


P2 I reckon will probably be around the 46-48 mark but P3 may be as low as 40
Reply 4
Original post by TODTEMPLE01
P2 I reckon will probably be around the 46-48 mark but P3 may be as low as 40


Imo P2 wouldn't be higher than 44 or 45
A lot of people found it hard
Personally I found P3 easier
Original post by mn9011
What do u think an A* will be ?


47marks
Original post by mn9011
Radiation

Q. Name a common fuel used in nuclear reactors? (1 Mark)
- Uranium(235)

Q. What happens to a nucleus undergoing fission? (2 Mark)
- The nucleus absorbs a neutron, becoming unstable which causes it to break down into two smaller nuclei, while releasing lots of energy and 3 extra neutrons in random directions.

Q. Cosmic Rays %? (2 Mark)
-15%

Q. Why someone might take in larger dose of cosmic rays? (1 Mark)
-Higher exposure to cosmic rays e.g pilot

Q. Give an example of man made radiation? (1 Mark)
-Nuclear waste from nuclear weapons

Q. Why were the teachers 3 readings different? (2 Mark)
- Different sources emit different amounts of radiation, so even a small change in location would result in a change
- Result might be anomalous.

Rods and polarization:

Q. Explain using polarization what happens to the silk and nylon rod when rubbed? ( 3 mark )
-The nylon rod has a higher polarization than the silk, therefore its electrons are transferred to the silk (because of its weak polarization). The nylon rod becomes positive, due to loss of electrons and the silk becomes negative due to gain.

Q. What would happen if a pvc rod was used instead of nylon? (1 Mark)
-silk would become positively charged instead of negatively, due to a higher polarization.

Q. What will happen to the reading of the same charged rods?: ( 3 marks)
-Increase


Q. Give a reason:
-The two alike charges will repel, so the rod on the scale will get a greater downwards force, which will increase the reading


Braking Distances:

Q. Thinking distance definition: (1 Mark)
-Distance travelled during the driver’s reaction time

Q. Braking distance by lorry? (2 Marks)
-24m or 48 m

Q. Force exerted by the brakes? (2 marks)
- 15 000 newton

Q. Name one control variable for the test? (1 Mark)
-Mass or surface area of the car

Q. What else can the student measure which would show braking distance? (1 Mark)
- Height of the weight from the ground

Q. What do the results in figure x tell you about the relationship: (2 Marks)
-As the force increases, the distance increases.
20 N of force is required to initiate a brake.



Decay:

Q. The student concludes that the decay is beta, explain how the results from the figure support this? (2 Marks)
-Beta is moderately penetrating hence, the penetration decreases as aluminum gets thicker.

Q. How could the student test for alpha? (2 Marks)
Use longer distances to test for change over distance, since alpha particles don't travel far



Electricity:

Q. Voltage passing through finger to car: (2 Marks)
-9000V

Q. Wearing wool over any other clothing will give you a smaller charge, two reasons why not: (2 Marks)
Lack of range
Anomalous result



LEDs

Q.LED symbol: (1 Mark)
-Little skip button inside a circle. Two arrows pointing to the top right, placed above the circle.

Q. Energy transferred by the LED: (2 Marks)
-12J

Q. Why are LED's cheaper to run? (1Marks)
-Halogen and filament produce a lot of heat as waste energy

Q. Explain by using ions and electrons why temperature increases resistance: (3 Marks)
-An increase in temperature means an increase in energy. The more energy particles (ions) have the more they shake, which makes it difficult for electrons to pass by, therefore increasing the resistance

Stars:

Q. What happens at a supernova? ( 1 mark)
-The star is unstable, so explodes

Q. Why doesn’t sun undergoes a supernova stage?
-(??) 1 mark

Q. After exploding the star becomes a ? ( 1 mark)
-Supernova



Q. 6 marker:
-Gasses gather up in space and begin to cluster in to the centre of their own gravity. (nebula)
Heat from pressure results in an early star formation (protostar)
Fusion begins to occur from hydrogen atoms fusing into helium nuclei, which triggers the beginning of the main sequence star.
Here it is stable for millions of years, and fuses all of its hydrogen to generate heat and light
Once hydrogen runs out, the star begins to swell and its outer layers cool off, giving it a red colour (Red Giant)
Here it fuses atoms up to iron
Once it runs out of atoms to fuse, it dispenses its outer layer of gasses and rocks (planetary nebula) into space
White dwarf -----> black dwarf (cooling) = death of the star
(6 Marks)

Q. Scientific theory question, why accepts some but not others?: (2 Marks)
- Some theories proven wrong through investigation
Some theories seem more reasonable than others
Some theories may have insufficient evidence, or the evidence is unreliable and irrelevant



Momentum:

Q. Explain why, using idea of momentum, the cannon moves back when it shoots the ball? (3 Marks)
-Momentum before= momentum after. Conservation of momentum means that the cannon will move back with the same momentum as the ball, but in opposite direction (but different speed and weight)

Q. Cannon balls momentum after 0.05 seconds: (3 Marks)
- 1000 kg m/s

Is this a level paper 2 2017
Reply 7
Is this the aqa a level paper 2 for 2017? :smile:

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