Hints offered by F Rafique

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Paper 1

Question 1

Hint 1: What are the initial and final speeds?

Question 2

Hint 1: Make a vector diagram with horizontal and vertical component vectors.

Question 3

Hint 1: Use the speeds just before impact and use Pythagoras' theorem

Question 4

Hint 1: What will be the acceleration graph look like if it is constant?

Hint 2: If the acceleration is constant, the speed is increasing so what does that mean about the vehicle's displacement?

Question 5

Hint 1: Which part of the string has to pull the greatest amount of mass?

Question 6

Hint 1: Momentum is always conserved, but is energy?

Hint 2: If external factors are ignored, there is only type of energy we consider.

Question 7

Hint 1: Try squaring both sides to deal with the square root, to make rearranging easier.

Question 8

Hint 1: l is measured in the same frame of reference as the object.

Hint 2: l' is the length measured by the observer.

Question 9

Hint 1: Value from the data sheet needed for this calculation.

Hint 2: Need to use two equations. The first one involves the speed of light.

Question 10

Hint 1: Does gravity cause attraction or repulsion of objects?

Hint 2: What is Dark Energy and what is it causing?

Hint 3: The greater the mass, the more gravitational force caused by galaxies. The more gravitional force, more acceleration.

Question 11

Hint 1: Straightforward calculation involving E, Q and V.

Question 12

Hint 1: Right hand rule as it is an electron.

Hint 2: Thumb - Force, Index - Magnetic field, Middle finger - Current

Question 13

Hint 1: Memory Test. Beta Decay is the evidence for existence of the neutrino.

Hint 2: W and Z bosons are associated with the weak nuclear force.

Question 14

Hint 1: a beta particle has a mass number of 0 and atomic number of -1.

Hint 2: If a beta particle has been emitted, what is the new symbol?

Question 15

Hint 1: For a current to be detected, electrons have to be emitted. For electrons to be emitted the minimum frequency has to be reached first.

Hint 2: Frequency has to be greater than 0 before a current can be seen.

Question 16

Hint 1: Energy of photons = work function + kinetic energy of photoelectrons

Hint 2: Once kinetic energy of photoelectrons are found, use
E_{k}=½mv² (mass on data sheet)

Question 17

Hint 1: path difference = (m + ½) × wavelength

Hint 2: path difference = 2.5 × wavelength

Question 18

Hint 1: Don't need to use the wavelength value.

Hint 2: Use data sheet for refractive index of water.

Hint 3: Use n = (v - air)/(v - water)

Question 19

Hint 1: How many different arrows can you draw between each level? (E4 to E3, E4 to E2 and so on)

Question 20

Hint 1: Find the voltage peak first.

Hint 2: Use V_{peak} = number of divisions × y-gain settings.

Question 21

Hint 1: Frequency is doubled and the timebase is halved.

Hint 2: Doubling frequency results in twice as many waves. Halving the timebase results in needing twice as many divisions to show a full wave (wave is stretched and doubled in length)

Hint 3: These two settings are shortening each wave and then doubling it again (making no difference)

Question 22

Hint 1: Find the resistance (using V = IR) and then find greatest percentage uncertainty between voltage and current.

Hint 2: Use the % uncertainty value (eg 10%) and find the % uncertainty of your resistance value. Change from percentage to a value.

Question 23

Hint 1: What is the parallel rule for voltage?

Hint 2: You have voltage and resistance and need to find power. Use your relationship sheet!

Question 24

Hint 1: Light can only go in the front of LEDs (the 'pointy bit')

Question 25

Hint 1: Are physical quantities liable to human/computing error which would result in uncertainties?

Hint 2: Can you take the exact same measurement every single time you repeat results or are they going to be a little RANDOM?

Hint 3: Systematic is when there is an error in apparatus that causes all results to be off by the same value.

Paper 2

Question 1

1a)i) Hint 1: Equations of Motion. Initial acceleration is until 0.50s.

1a)i) Hint 2: Use SUVAT to write down knowns and unknowns for between 0 and 0.50s

1a)ii) Hint 3: Use SUVAT again to find s

1b)i) Hint 4: momentum = mass × velocity

1b)i) Hint 5: change in momentum = momentum before - momentum after

1b)i) Hint 6: What are the speeds before the bounce at 0.50s and after?

1b)ii) Hint 7: You have time, momentum before and momentum after.

1b)ii) Hint 8: Make sure you use the time of the bounce itself, not how long it takes to hit the ground.

1b)ii) Hint 9: Still need a hint? It is Ft = mv - mu

1c) Hint 10: It is always accelerating negatively (at the same rate) between 0s and 0.50s and between 0.77s and 1.18s.

1c) Hint 11: Between 0.50s and 0.77s it is accelerating positively (at the same rate)

Question 2

2a) Hint 1: Use W = mg

2b) Hint 2: Draw a vector diagram with the vertical tension (same as weight) as a vector going straight up. Add the tension in the rope as a vector with 15° between them.

2b) Hint 3: You now have a right angled triangle with Tension in the rope being the hypotenuse and the vertical tension (540N) being the adjacent and the angle between being 15°

2b) Hint 4: Using trigonometry, vertical tension = tension in rope × cos(15°) [you need to rearrange]

2c) Hint 5: As the angle decreases, cosine of the angle increases so now the tension must be ... (look at your previous formula from part (b)

Question 3

Hint 1: First of all, write down the areas of physics you think this questions relates to. Also start by saying which parts of the statement you agree/disagree with.

Hint 2: These should include (but are not limited to): momentum and impulse, forces, d = vt and a bit of energy

Hint 3: So think about the conservation of momentum equation of mass before = mass after. If you need to change the momentum of a ball from a negative to a positive (one direction to the other if it is travelling initially towards you) then some of the force applied to it isn't going to be used to kick it the other way.

Hint 4: If the ball is initially travelling towards you, you apply impulse to it (force over time) and you will first need to bring it to rest, before the force can cause it to change direction. If you apply the same amount of force in both situations mentioned, then in which situation is more of the force able to cause the ball to go faster in one direction?

Hint 5: If a ball has a greater velocity to begin with, how does that effect the distance travelled?

Hint 6: You can also talk about potential energy being stored when the ball is travelling towards you at the moment of impact. The ball is compressing slightly (like a ball that is dropped from a height, just as it hits the ground) and it has the potential of moving again.

Question 4

4a) Hint 1: Distance = radius of earth + distance to satellite

4b) Hint 2: F = Gm_{1}m_{2}/r²

4b) Hint 3: the value for G is in the data booklet

4c) Hint 4: W = gravitional force [which you have]

4c) Hint 5: You want to find g and you have the satellite's mass…

4d) Hint 6: Two changes: mass is ¼ and the distance is ½. You can substitute these as values into the equation to see what happens to the gravitional force.

4d) Hint 7: If mass is ¼, that results in a quarter of the force and as the distance is squared, ½ distance means it quadruples the force (as its now divided by ¼)

4d) Hint 8: Mass is quartered and distance quadruples so that means …

Question 5

5a)i) Hint 1: Not photoelectric

5a)ii) Hint 2: You want to find observed frequency

5a)ii) Hint 3: Travelling away, so denominator of fraction is: v -
v_{source}

5b) Hint 4: Substitute the numbers in correctly. Be careful of powers and rearranging. You could try re-arranging before substituting in values.

Question 6

6a) Hint 1: Greater temperature means more heat energy so the energy emitted is always higher.

6a) Hint 2: It is a hotter star so that means more energy, so more frequency. How does this affect peak wavelength?

6b) Hint 3: Use each row of data and plug it into the equation given.

6b) Hint 4: Once rearranged, it becomes T × peak wavelength = consistent value.

Question 7

7a)i) Hint 1: Fundamental means it's not made up of any smaller particles.

7a)ii) Hint 2: Memory Test! The word begins with 'F'.

7a)ii) Hint 3: Still stuck? Next letter is 'E'.

7a)ii) Hint 4: Really? Fine, next is 'R'.

7a)ii) Hint 5: Fourth letter is 'M'.

7a)ii) Hint 6: Fifth letter is 'I'. If you've needed all of these hints, then consider revising the standard model.

7b) Hint 7: The quarks inside the pentaquark are listed at the top of the page.

7b) Hint 8: There are 2 up quarks so it becomes 2×(2/3) - 1/3 + 2/3 - 2/3

7c)i) Hint 9: Memory Test! The word begins with 'M'.

7c)i) Hint 10: Next letter is 'E'.

7c)i) Hint 11: Next letter is 'S'.

7c)ii) Hint 12: You need to find the longer time that is observed. Is that t or t'?

7c)ii) Hint 13: It is t'

7d)i) Hint 14: You have the amount of eV that a pentaquark has. It also tells you how much one eV is equal to in J. Two numbers. What do you do?

7d)i) Hint 15: Multiply them together

7d)ii) Hint 16: You have the energy of the pentaquark and it is asking for mass. What equation has these two quantities?

Question 8

8a) Hint 1: It is either fission or fusion …

8a) Hint 2: … and it's definitely not fission

8b) Hint 3: Find the mass lost = mass before - mass after

8b) Hint 4: E = mc²

8c) Hint 5: You have the total energy that the sun emits at the top of the page and your answer to part (b) is how much energy one reaction makes.

8c) Hint 6: Divide one by the other

Question 9

9a)i) Hint 1: This is a four mark question so it must not be completely straightforward. What is the extra mark for?

9a)i) Hint 2: You have the energy lost by the electron which is ALSO the energy of the photon (difference in energy levels).

9a)i) Hint 3: What physical quantity that is given to you on the data sheet can you use for spectra?

9a)i) Hint 4: It is planck's constant

9a)i) Hint 5: E = hf to find the frequency and then what can you do to find wavelength?

9a)i) Hint 6: speed = frequency × wavelength . If you needed all the hints for this question, then consider revising spectra

9a)ii) Hint 7: Another four mark question ... what is the extra step to do?

9a)ii) Hint 8: What are the values that you know and which irradiance equation can you use?

9a)ii) Hint 9: You have the diamater so you can find the ... ?

9a)ii) Hint 10: … the area of the circle

9a)ii) Hint 11: Then use I = P/A

9b) Hint 12: Asking for the experiment to find the inverse square law. So, three steps on how to get to the graph of Irradiance against 1/d²

9b) Hint 13: Step 1: Get your values of irradiance for different distances. That is the first step - what do you next?

Question 10

10a) Hint 1: Smallest angle = less diffraction (spreading of light)

10a) Hint 2: Which quantity about different colours of light would result in less diffraction?

10a) Hint 3: It is wavelength, so which colour of light has the smallest wavelength?

10a) Hint 4: Blue. State the colour, and then explain why.

10a) Hint 5: Smallest wavelength so path difference is smaller [use equation: d sin(θ) = m × wavelength] so spots are closer together

10b)i) Hint 6: Straightforward equation, with no tricks. Write down your knowns and unknowns.

10b)ii) Hint 7: Look at your data sheet for colours of light and their corresponding wavelengths

10b)iii) Hint 8: If a larger slit seperation is used, how does this affect the angle? (rearrange the equation to make the angle the subject, if you are not sure)

10b)iii) Hint 9: It is a smaller angle between maximas so what does that mean in terms of measuring accurately?

10b)iii) Hint 10: More difficult, so uncertainties increase

Question 11

11a) Hint 1: Straightforward equation of n =
sin(θ_{air})/sin(θ_{diamond}) and then rearrange

11b) Hint 2: Another straight forward equation. Substitute in the values and no rearranging required.

Question 12

12a)i) Hint 1: This is a 'state' question, so no calculations are required. What is the definition of EMF?

12a)i) Hint 2: It is the stated value of the cell before any lost volts.

12a)ii) Hint 3: Write down knowns and unknowns. You have E, V and I, so what is your equation?

12a)ii) Hint 4: use E = V + Ir

12a)iii) Hint 5: Switch is closed, so current can now flow through the supply into the circuit. If there is a resistance in the cell and there is a current flowing through it, what do you have?

12a)iii) Hint 6: Current? Resistance? Multiply them together …

12a)iii) Hint 7: Voltage! So there is voltage being used in the supply before it gets to the circuit.

12b)i) Hint 8: Combine E = V + Ir and V = IR to form one equation [replace V with IR]

12b)i) Hint 9: This becomes E = I(R+r) and you can then find I

12b)ii) Hint 10: You have to find P and you have I and R. Look at your relationship sheet.

Question 13

13a) Hint 1: You have capacitance and voltage. Be careful of prefixes and if you still need help, look at the relationship sheet.

13b) Hint 2: Greater resistance affects current in what way?

13b) Hint 3: Lower current, so you have a lower starting current

13b) Hint 4: Greater resistance means more opposition to current, so will take it take the same amount of time to discharge, or shorter or longer?

13c) Hint 5: Look at the relationship sheet and the three equations to do with capacitor energy

13c) Hint 6: Which of these variables could you change that doesn't involve changing the capacitor? There is only one.

13d) Hint 7: This is probably one of the nicer knowledge of physics questions. So assume the vehicles are electrons and as the vehicles enter the car park (capacitor), they will first fill up all the spaces they can. This can be compared to electrons building up charge on the parallel plates.

13d) Hint 8: As a capacitor charges, it stores energy between the plates so the car park could be stated to be storing vehicles (which have potental energy)

13d) Hint 9: Work is done in charging the capacitor and the vehicles (electrons) need to have work done for them to move at all.

13d) Hint 10: Unlike the car park; however, once a capacitor is fully charged (full) current can no longer flow through it. Once the car park is full, vehicles can still flow through it and exit on the other side.

Question 14

14a) Hint 1: For conduction to take place in these three materials, electrons have to make it to the conduction band and get across the band gap.

14a) Hint 2: Which solid would make it easy for electrons to get from valence to conductions bands?

14a) Hint 3: The easier it is means there is more conduction. Therefore this means that Solid X is ...?

14b) Hint 4: In a semiconductor, what can you say about the energy/band gap?

14b) Hint 5: Because of this, the electrons have enough _________ to go from which band to which band?

14c) Hint 6: Semiconductors normally act more like insulators so you'd dope them if you wanted them to act like what instead?

14d) Hint 7: Comparing silicon to copper so just divide one by the other.

14d) Hint 8: Whatever answer you obtain, you need to use the power of 10 in that answer and say it is that many orders of magnitude greater.

Question 15

15a) Hint 1: Just timing one swing wouldn't be very accurate so what would you do?

15a) Hint 2: Time several swings and count how many there are

15a) Hint 3: How would you use that data to find the time for one swing? (one period)

15b)i) Hint 4: Skills check so just make sure your scales are consistent and points are plotted accurately. Use at least half the page and remember labels and units.

15b)ii) Hint 5: Depends on how well you did your graph, but be sure to read the values accurately from your graph

15b)iii)A) Hint 6: Smallest value on your graph for period

15b)iii)B) Hint 7: You cannot just say 'take more measurements' or 'repeat experiment', although doing more measurements is accepetable if you're more specific

15b)iii)B) Hint 8: So if you do more measurements per value of 'h', would that be okay?

15b)iii)B) Hint 9: Yes it would. You could also do more measurements over a bigger range.

15c) Hint 10: So find the value of T when h = 0.30m from the table and substitute it in.

Did this hint help?