2016 | OCR A2 Advancing Physics B | G494 & G495 | 20th & 28th June

That was certainly interesting... Lots of wordy questions. I couldn't do the exponential disproof at all because the data that I used actually did follow an exponential relationship.. I'm fairly certain I also mucked up the double mass half pressure question where I chose the line with gradient 1. Fairly certain that gradient 1/4 was correct. Oh well, I just hope that G495 is a bit better because I really need an A.

I put 0.5 and 8.

definitely 0.5 but not entirely sure about 8.

And to the other guy about the exponential disprove, I found that the p.d halved at like 2 s, from 6V to 3V, but then at 4s (i.e. supposedly 2 half lives later) it went down to 1V instead of 1.5V.

I would say standard boundaries, around 46 or 47 for an A

nah it was A, the steepest line



yea it's that

I would say standard boundaries, around 46 or 47 for an A

I got gradient as 1/4

Anyone remember more from the bullet question? Like which section it was in etc? I can't remember any of it and I just wonder wether my mind went blank or I missed it out.

pV = NkT => V = NkT/p, so volume is proportional to N (which is proportional to mass) and inversely proportional to pressure. The graph was volume vs. temperature, and it said the mass doubled and the pressure halved. So the volume-temperature gradient increased by a factor of 4.



it was the last question I think

Well based on the usual grade boundaries I'd say 40 for an A, 39 for B, 38 for C, 37.5 for D, 37 for E and <37 for a U

How many marks?

pV = NkT => V = NkT/p, so volume is proportional to N (which is proportional to mass) and inversely proportional to pressure. The graph was volume vs. temperature, and it said the mass doubled and the pressure halved. So the volume-temperature gradient increased by a factor of 4.




it was the last question I think

pV = NkT => V = NkT/p, so volume is proportional to N (which is proportional to mass) and inversely proportional to pressure. The graph was volume vs. temperature, and it said the mass doubled and the pressure halved. So the volume-temperature gradient increased by a factor of 4.



it was the last question I think

What about the one with helium? What did u do for the last two questions of it

No but A was a directly proportional line, this would imply the gradient didnt change at all

hmm

you had to show it had 0.2J after the impact, that's probably 2; then you had to calculate the speed from conservation of momentum, that's probably 3. Then there were two 2-markers. So it's about 9 marks.

No but A was a directly proportional line, this would imply the gradient didnt change at all

10 questions, the show that question was 3 marks due to the assumption you had to make

for that question the right answer was 100% the highest line, with end point 4 times as high as the original line.

ah cool, 10 marks u mean tho right

For "discuss the Boltzmann factor", I calculated it, and it was something like 10^-44 so I said it was negligible, so theoretically the helium atoms should escape eventually but it will take a very long time.

Can't remember the other question D:



they were all directly proportional lines..?

if you mean the gradient was 1, it doesn't matter, because we were looking at it compared to the C line, whose gradient was 1/4, and 1/4 * 4 = 1