2016 AQA Physics P3 higher tier Unofficial Markscheme 2016

1.5 = 1/sinC
sinC = 0.666...
C=42(2sf)

No it was 1.1 nm

Would you care to explain how you got that answer?

i got to 500m/s on the speed of ultrasound..

I got 1600 m/s for ultrasound questionn and explained earlier in the thread how.

I can't remember seeing a question about describing the image? I did PH3HP, would someone assure me that this wasn't on this paper? Also, could someon explain how they got the answer for the moments to be 0.9. I got 0.48 as you can't add the distances together, I did:

1.5 × 0.20 + 1.5 × 0.12 = 0.48 Nm and so the force was 0.48 on chain??

I am also wondering about this question. As the pedal was apparently stationary I assumed the moment of the chain on the pedal and foot on the pedal were equal (as they acted in opposite directions?) so did F1 x D1 = F2 x D2. I can't actually remember what I got as the force but it may have been 0.9N. I don't have a clue if it is right though! Sorry if this is completely wrong. Hopefully it is correct but what you did seems good....

I'm talking about the same question yeah, but what I couldn't see is that f1 ×d1 can't have equalled f2 × d2 because the perpendicular distance was that much greater so how could it have been stationary? And also, the chains moment would of had to act downwards because there was nothing substantial pushing it upwards, as the foot pushing down would have caused the chain to be pulled down?

There was a question about like light intensity and why the same light wave changed I think it was 2 marks, it had route A and B what was the answer?
Posted from TSR Mobile

I don't really know, but didn't the diagram show the chain moving up? 😂😰😖 I didn't really see how it could have either but I could have sworn there was an upward arrow along the chain on the diagram..... 😀


Posted from TSR Mobile

Yea there was an upward arrow it confused the f*ck out of me ngl. But still, if there was a downward force acting on the pedal and that was the only pivot then there's no way that there could have been both an upward force and a downward force? Surely? They really screwed with my head

There was nothing on Flemings left hand rule
Please READ THE TITLE OF THE DISCUSSION before commenting on something not included in the paper and giving me a literal mini heart attack.
Kind regards.


Posted from TSR Mobile

Which paper did you sit? there was one question asking which direction the force from the motor effect would be- it was downwards

There are two slightly different papers. Some people sat, like me, PH3HP, and other schools did further additional unit 3. It sounds weird but they are always slightly different.


Posted from TSR Mobile

So I can get an A?!

Right, that exam was awfully hard... Let's make a mark scheme guys. Please put in any questions or answers you can, preferably with question number if you can remember it. I'll try to keep updating it as best I can, but i'm only human

ALSO, THIS MARK SCHEME IS VERY INCOMPLETE, SO DON'T EXPECT IT TO BE 100% CORRECT


1.
a) Why was electromagnet better for sorting rubbish? (1 mark)
Because it can be switched on and of/activated and deactivated OR it is more powerful than a normal magnet
b) How can the students use this equipment to create an electromagnet, and test it - and vary its strength? (6 marks)
Wrap Insulated wire around nail. Suspend in the wooden clamp. Attach to power supply with connectors. put paperclips under and increase power until paperclip is attracted OR set to certain power and lower until paperclip is attracted. Then repeat with different height/power.



Unknown Question numbers/answers:

2 - Radiation/ultrasound Questions
Calculation: 0.08m or 0.04m divided by 110x10^-6 or 50x10^-6, We're not sure yet (but I think the answer is 400 m/s) (3 mark)
Why is X-rays not used with unborn babies?: X-ray causes ionisation which are damaging to the foetus' cells, causing them to become mutant and divide uncontrollably. This leads to cancer. (3 marks)
How does an X-ray work question: X-rays emitted toward a photographic CCD. Hard tissue like bone absorbs the rays, making them white on the image, but softer tissue allows them to pass through (3 mark)
Question on wavelength: Shorter (1 mark)

3 - Stability Questions
What is meant by the 'centre of mass'?: the point where the mass appears to be concentrated (1 mark)
Why is tower B more unstable than A?: narrower base, higher centre of mass (2 mark)
Why doesn't this tower fall over?: The line of action of the weight lies within the base so there is no resultant moment causing it to topple (2 mark)

4 - Foot peddle and drums/Moments questions
What is meant by moment of the force: A DICTIONARY DEFINITION: "A measure of the turning effect produced by a force about an axis.The magnitude of the moment is the product of the force and the perpendicular distance from the axis to the line of action of the force" (1 mark)
1.5 N force from toe. 0.20m from pivot to the chain. 0.12m from pivot to toe: 0.9N??? (3 marks)
Graph showing different lengths of drum hinges compared to volume of sound produces at different forces (3, 6, 9 newtons) (2 mark)

5 - Eye correction/lenses/Ray trace diagram questions
Critical angle (2 significant figures): 1/1.5 = 0.6666.. sin^-1(0.6666..) = 42 degrees (3 mark)
(image was formed behind object, magnified, and was virtual because the lines on the other side of the lens did not converge)??? (3 mark)
Reason for long longness: Lens in eye too weak OR eyeball too short (1 mark)
Source of energy for cutting cornea: LASER (1 mark)
(Not too sure, but there was an M/N object question) (3 mark)
C/B lens question: draw the lens fatter??? (1 mark)


Grade boundaries are looking low too. from a purely personal viewpoint (don't take these 100% seriously) these are what i think the boundaries will be:

A* - 40
A - 34
B - 28
C - 23
D - 17
E - 12


(P.S. Below are some mark schemes for the P2 exam you wonderful physicists might want)
http://www.thestudentroom.co.uk/showthread.php?t=4171131
http://www.thestudentroom.co.uk/showthread.php?t=4171228
http://www.thestudentroom.co.uk/showthread.php?t=4171902 --- This one is probably the best, well done to lily628 for making it