x Turn on thread page Beta
 You are Here: Home >< Physics

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

1. (Original post by boyyo)
will there be any model answers for section A??

Also for the questioon that said to right two thinngs to make the sentence about volume being inversely proportionl to pressure; did anyone say mass of the gas? I couldnt think of another one so thats what i put down
I said tempreture and moles have to be consatnt, is that right

??
2. (Original post by boyyo)
will there be any model answers for section A??

Also for the questioon that said to right two thinngs to make the sentence about volume being inversely proportionl to pressure; did anyone say mass of the gas? I couldnt think of another one so thats what i put down
1. Under the same temperature.
2. The mass of the ideal gas must have the same mass. (ie. constant mass)
3. Density was 2 x 10^-24

Posted from TSR Mobile
4. (Original post by Mango Milkshake)
I said tempreture and moles have to be consatnt, is that right

??
Yes, because if the number of moles is constant then so is mass.
5. I put elastic collisions
6. (Original post by Amy-Jo)
I put elastic collisions
That's already assumed because the question said "ideal gas".
7. (Original post by Mango Milkshake)
I said tempreture and moles have to be consatnt, is that right

??
erm idk i put constant mass
8. (Original post by boyyo)
erm idk i put constant mass
Same thing. Correct

Posted from TSR Mobile
9. what was the density of the gas?
i got 1.2 something?
10. (Original post by Jon1234321)
I also got 1.2x10^8 AU for the penultimate quasar question but starting to think this is wrong after looking on here

For those who got the other answer (2.4 something) could you tell me how u did this question as i am really confused.
I can't remember the values they gave us but it was like, intensity of sunlight at earth is X times greater than light intensity from the Quasar and the Quasar is Y times brighter than the sun.

So I set up the equations using inverse square law

Sunlight intensity at Earth: 1 x 1/(1AU)^2
Quasar intensity at Earth Y x 1/d^2 = 1/X
Then rearrange to make d the subject

Its hard for me to properly explain it, but I'm basically making the Sun a standard with its light intensity at Surface of Earth and power =1
so intensity of Quasar at Earth is Intensity of Sunlight at Earth/X
brightness of Quasar is Y

When I say Brightness I mean light intensity at the Sun or At the Quasar or there power output or whatever. I don't need to know that anymore anyway.

A lot of that may not make the most sense and it may not help much but I'm pretty sure I did something like that.
11. (Original post by FireBLue97)
1.8x10^4 -1.5510x10^4 gives 2.1x10^3
next part 2.5x10^4
1.8x10^4-1.55x10^4 gives 2.5x10^3 lol?

next part is 2.1x10^3
12. (Original post by boyyo)
will there be any model answers for section A??

Also for the questioon that said to right two thinngs to make the sentence about volume being inversely proportionl to pressure; did anyone say mass of the gas? I couldnt think of another one so thats what i put down
Constant temperature
Closed system
13. (Original post by tanyapotter)
what was the density of the gas?
i got 1.2 something?
2 x 10^-24

Posted from TSR Mobile
14. (Original post by boyyo)
erm idk i put constant mass
I think both mass or moles is right
15. (Original post by tanyapotter)
what was the density of the gas?
i got 1.2 something?
yeah density was either 1.20 or 1.21 depending on what you did
16. (Original post by tanyapotter)
what was the density of the gas?
i got 1.2 something?
yeah I got that too.

Seemed to be a lot of small answers like i remember getting 0.06 and some others like that
17. (Original post by Yo12345)
2 x 10^-24

Posted from TSR Mobile
dont think this is right
18. (Original post by tanyapotter)
what was the density of the gas?
i got 1.2 something?
I got 1.2kgm-3 I think
19. (Original post by Yo12345)
2 x 10^-24

Posted from TSR Mobile
1.2 i think
20. What was the moles of gas? I got 0.067 or 0.0016/0.024. Then used mass is molesxmolar mass to get the mass of air, then density over the volume from the previous part of the question

And I used pV=NkT for the volume, because it didn't give the moles initially

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: August 19, 2016
Today on TSR

### Loughborough better than Cambridge

Loughborough at number one

### Can I date a girl with no boobs?

Poll
Useful resources

Can you help? Study help unanswered threadsStudy Help rules and posting guidelinesLaTex guide for writing equations on TSR

## Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE