AQA Physics PHYA5 - 28th June 2016 [Exam Discussion Thread]

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justalawyer1998

Original post by TheLifelessRobot

Lol all you had to do for the moles question was 0.0012/0.018 for the moles. Where 0.0012 and 0.018 were the volumes given. You could just use p1v1/t1 = p2v2/t2 for the part earlier, no need to calc the constant.

You can do either method

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Reply 801

FireBLue97

Original post by kingaaran

I got 0.066 moles I think. You had to work out the constant of proportionality between P, V and T, use the formula to work out the new volume in the first part and divide the constant by 8.31 to get the number of moles in the second

me too then u multiplied this by the kgmol^-1 in the question to get mass and then divide by the 0.0016m^3

did u get 3.6x10^ something

Reply 802

clarkey500

I'm actually pretty pleased with how that exam went! I'm also pretty glad that my last exam was nice compared to some of the sorcery AQA and Edexcel have come up with in their papers.

I did Astro as the part B and I think that paper was probably the easiest of the two; the 6 marker on comparing the 3 stars was really nice!

The Nuclear and Ideal Gas stuff was also fairly nice and the 6 marker in that about Rutherford was pretty good - althogh I think I probably did better in the Astro 6 marker!

Overall a nice exam to end on! :smile:

Reply 803

crashMATHS

Original post by FireBLue97

for the tick boxes question it was to break all intermolecular bonds as the others implied the same thing ie increase in speed kinetic energy.

Increase in temperature question molecular increase in speed as they gain kinetic enrgy up to a maximum value i think u had to state max value her possibly.

0.034 for some distance question in turning points
and for the question after the proof of 1-v^2/c^2 it was the 3km and length contraction so some 0.036 m etc smaller value in meteres as asked.

I'm pretty sure it breaks some of the intermolecular bonds, because breaking all suggests it is a gas, rather than liquid.

I got that the distance increased, because doesn't length contraction say that an object moving appears to a smaller than it is according to the observer?

Reply 804

tanyapotter

Original post by Mattematics

Didn't correct for count rate, 1 or 2 gone.
Unit for latent wrong - 1 gone.
Detecting beta - 1 gone.
6 marker - default 2 gone.

Used wrong method for specific charge - 3 gone.
Current - 2 gone.
6 marker - default 2 gone.

So 13 lost. Then presumably losing however many more for mark schemes that are stupidly specific or contradictory.

Probably got around 50, which should hopefully be around an A.

is 50 normally an A?

Reply 805

FireBLue97

was it 660 for the counte rate?

25 for current

Original post by FireBLue97

me too then u multiplied this by the kgmol^-1 in the question to get mass and then divide by the 0.0016m^3

did u get 3.6x10^ something

I did the mass divided by the volume. Not the number of moles, because the question said it had one mol initially, so I just assumed we had to times by 1? I'm not sure though, as I don't really get chemistry

Reply 808

Mattematics

Original post by tanyapotter

is 50 normally an A?

Depends on the paper. It's usually around that but it's been higher before.

Reply 809

Skygliderjack

Original post by HughBax

What did people get for the penultimate question on Astro? (the distance to the Quasar) I think I had something like 2.14 x10^14 AU but I may have remembered wrong

I'm pretty sure I got that :smile:

Reply 810

TheLifelessRobot

Original post by kingaaran

If you are moving at rest relative to the object (i.e. moving with it at the same speed) the length you examine is smaller.

Reply 811

WashingPowder

, I think alot of people when calculating specific charge are forgetting you cannot caluclate v using ev= 1/2 mv^2 , because this would require you knowing the electrons charge/ mass which avoids the whole point of calculating specific charge.