PHYA5 ~ 20th June 2013 ~ A2 Physics

Did people get about 28 for the density ?

Yes

Did people get about 28 for the density ?

I'm sure on the de Broglie question with the proton and electron that it said to ignore relativistic effects.

For the turning points people, what did you all put for the very last question about travelling faster than light? I think I dropped marks on it, even though it was basically a gift marks question

As v --> c, m-->infinity (show equation as proof).
So kinetic energy tends to infinity, which is impossible to get.

Yeah, I figured :/

I thought I was being dead clever in the exam, because it talked about exceeding the speed of light rather than approaching it, so I answered it by saying that if v>c , 1 - (v^2/c^2) is negative, so its square root is undefined. Do you reckon I'd get marks for that?

Also, nice name :P

Did anyone else notice how easy the applied physics paper was? I'm pretty sure the only question that made me think was the last one

p1v1/t1 = p2v2/t2

You have all except v2 rearrange for that.. I also added the pressures up for p2 because it was other wise too small :\ (similar to the q from the specimen paper, look at it if you don't get why I did so)

After getting v, use m=d x v to get mass..

What answer did u get with this. I used a different method and worked out the moles which were 3.3 and times that by 0.048kgmol^-1 and my answer was 0.16

70 something.. Actually we might be right since some other peeps got the same on here.

Was the explanation simply because the focal length was longer?

Did anyone else notice how easy the applied physics paper was? I'm pretty sure the only question that made me think was the last one

I got 4.2 :\ yeah you had to multiply by the kg per mol in prev question. I probs got the volume wrong