2016 AS physics new spec MARK SCHEME

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I now know the paper is alright but I made so many mistakes which annoys me, think I got about 35-40 :/

Some more answers (I believe)

1 f) Why is the decelerating force of the jet engine not constant in reality? (OWTTE)

- As the Jet slows down less air enters the engine
- So less change mass
- So less momentum and thus less force

2 b) Why does the chocolate only melt at specific points?

- The microwaves form stationary waves
- This means that there are antinodes and nodes created
- At points of constructive and destructive interference respectively
- At the antinodes the maximum vibration is seen
- So the most heat
- So the chocolate melts at the antinodes

3 d) (I believe)

The resistance of the probe increases by 1.6% what is the percentage increase in diameter?

- New resistance is 1.016 x old resistance
- Thus new area is 1/1.016 x old area (from A = pl/R (as resistivity and length remain constant))
- So new radius is Sqrt(1/1.016) x old radius (from Pi*r^2 (Pi is constant))
- So new diameter is also Sqrt(1/1.016) x old diameter = 0.99209 * old diameter
- 1 - 0.99209 = 0.00791 (3 s.f.) <-- this is the change in diameter
- multiply by 100 to get a percentage change of 0.791% (3 s.f.)

I'll probably add some more after C2 tomorrow.

Any mistakes please feel free to correct them :smile:

Also if you want to add these to your document feel free, I won't be able to as I don't have access to google drive, but I imagine getting all the answers together could be a good idea.

Reply 22

marldor

Original post by somerandomer654

Hey,

For material D, wouldnt the cord just stretch to such an extent that the person hits the ground? So it must be C?

The graph had no scale. Your judgement was based on shape alone.

Reply 23

somerandomer654

Original post by marldor

The graph had no scale. Your judgement was based on shape alone.

Fair enough, but wasn't that the whole point? Judge the four by how they are relative to each other? It might be D, ngl but it also had much lower tensil stress compated to C.

Reply 24

BainesyA

Original post by Lola1244

where did it say 2876??
i got 9 times ten 23

For that question there was a paragraph of text, most of which was irrelevant, however it gave the value as 3876MeV (Not 2876 as stated in the previous post)

Reply 25

FlatearthFTW

Original post by somerandomer654

Fair enough, but wasn't that the whole point? Judge the four by how they are relative to each other? It might be D, ngl but it also had much lower tensil stress compated to C.

When you manufacture cords out of material D it would be much thicker and have a much higher tensile strength.

Reply 26

FlatearthFTW

Original post by BainesyA

For that question there was a paragraph of text, most of which was irrelevant, however it gave the value as 3876MeV (Not 2876 as stated in the previous post)

It was 3782

Reply 27

MathsMPhys

Im not sure bout your the answer for the wavelength question i used my wavelength as 12cm..0.12m do you think they'll accept that
I think i might have gotten like 58-62 in that one
Silly mistakes

Reply 28

MathsMPhys

Any predictions for grade boundaries??

Reply 29

ben_urwinator

Original post by Science_help

did you convert the joules from ek max in previous question to ev?

Yeah

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Reply 30

MathsMPhys

Btw your answer to why theres two photons produced is wrong.. conservation of charge and momentum are not affected by photons as they have no mass and no charge...
Its due to there being photons produced by the annihilation of two different particle antiparticle pairs

Reply 31

lukearcus

Original post by MathsMPhys

Although photons have no mass they do actually have a momentum (calculated by using de broglie's equation). So in annihilation when a particle and antiparticle collide momentum must be conserved and if they collided head on the only way momentum could be conserved is if 2 photons were produced travelling in opposite directions.

Reply 32

marldor

Original post by somerandomer654

Fair enough, but wasn't that the whole point? Judge the four by how they are relative to each other? It might be D, ngl but it also had much lower tensil stress compated to C.

D would be for the bungee, as you need the most extension with the least force and for it to not pass the elastic limit as it would need to return to the normal. And you could argue a, b and to an extent c.

Reply 33

MathsMPhys

Photons do have momentum but tht isnt something that will come up in AS level physics as thats about special relativity nd not de broglie so tht answer for this exam wouldnt hold

Reply 34

MathsMPhys

But yh lukearcus nice mark scheme you reassured me bout few of my answers especially the momentum ones at the very start of the paper thought i was wrong when tlking bout direction of air changing aha

(edited 7 years ago)

How was core two?

Easy i generally better at maths than physics tbh how did you find it did you do edexcel?
Momentum of photons is given by E/c at m=E/c^2, so p=E/c, ...