AQA Physics A - PHYA4 (11/06/12) - Exam thread

My friend says 'You needed to calculate the force the [falling] sand exerted on the basin, plus the mass of the basin and the sand already in it. The previous question had an answer in Ns, so divide that by 10(s) and add it to the 2 masses.'

I don't think that's right because the previous question asked the momentum per second so dividing it by 10 seconds would give the momentum for a tenth of a second I think?

Reply 581

seanninetytwo

Original post by Chris250

I used SUVAT to find out how long some sand remained airborne, complete guess but it got my 3.82kg

Yeah did exactly the same in the last minute when I figured i had notthing to lose. Was so happy it worked even though it was only a mark. Probably because the rest was so tough had to work hard for a lot of marks. No one in my exam room found that to be a nice test, general consensus seems the same too. I'm hoping for a c and an a in unit 5 which im stronger at

Reply 582

rub em out

7

Original post by number23

I found the first written question difficult, and like the second multiple choice one about the alpha particle was weird... did people get rubber>lead>copper as the order they fall in for the other question?

how did people find the electric fields question?

Do you remember whether that was A or not? I know that rubber lead copper was the right answer but im freaking out that I might have put the wrong option down!

And yeah I hated the alpha particle one, I ended up putting B

Reply 583

number23

15

Original post by rub em out

Do you remember whether that was A or not? I know that rubber lead copper was the right answer but im freaking out that I might have put the wrong option down!

And yeah I hated the alpha particle one, I ended up putting B

i think i put D for the magnetism one, and maybe a for alpha :s

Reply 584

SmithytheDrummer

6

2a) Direction of force on electron
b) Does the magnitude of the force on the electron change during the motion.
c) not sure...
d) Are the initial acceleration of the particles different?
E) How does the acceleration of the particles change

Reply 585

Circadian_Rhythm

14

for the alpha particle question, was it's speed which was lowest? I think that was B or C?

Reply 586

yayayapiolin

Original post by rub em out

I don't think that's right because the previous question asked the momentum per second so dividing it by 10 seconds would give the momentum for a tenth of a second I think?

f=ma

F from previous question divided by g, gave 0.17 which seemed to be the ghost extra weight so I just thought that was the right method. I guess the 0.3 kg that fall in 1 second exert a force on the basin. There was something in the question that gave it away, so it was inelastic.

The whole thing was very very hard
I can say goodbye to Leeds Uni after that paper.

Reply 587

number23

15

Original post by Circadian_Rhythm

for the alpha particle question, was it's speed which was lowest? I think that was B or C?

i thought it was accelerating?

Reply 588

Josh1993

Momentum before = momentum afeter

therefore find the velocity of beaker.
use a = v-u / t , to find acceleration.
(newtons third law meaning R will exert an equal but opposite force)

find f using f=ma

f/g = m

This was the extra mass in addition to the sand.

Hope everything went well. :smile:

(edited 11 years ago)

Reply 589

Liam_W_

Original post by number23

i thought it was accelerating?

I put acceleration was zero, I didn't think it could be the others. If speed was minimum, KE is at minimum therefore potential is maximum, so if C is right D would be right.

Could be completely wrong, made new branches of physics due to the test peeing me off!

Reply 590

yylung

I didnt know how to show the velocity to be 5.6ms^-1 :frown:

Reply 591

Christd

How low can the grade boundaries fall? The boundaries for this exam are already quite low and i haven't seen them fluctuate very much over the last few years...?

Reply 592

Troll the Trolls

Original post by yylung

I didnt know how to show the velocity to be 5.6ms^-1 :frown:

uvast

messed up on the mass question, 2ev of neon question and its part b, and i only got 4 b's on the multichoice :frown:

loads of a's

Reply 593

number23

15

Original post by Liam_W_

I put acceleration was zero, I didn't think it could be the others. If speed was minimum, KE is at minimum therefore potential is maximum, so if C is right D would be right.

Could be completely wrong, made new branches of physics due to the test peeing me off!

i put the one about accelerating... u just worked out the ones that def weren't right

Reply 594

sconter

11

Original post by yylung

I didnt know how to show the velocity to be 5.6ms^-1 :frown:

that took me way too long lol.

Reply 595

robthefool

12

Quite a few of the multiple choice q's had come up before, the order was rubber,lead, copper (or from right to left)

But damn that paper was a bitch... the neon question - wtf? the prove the mass is 3.6kg or whatever - wtf? and i think that there was another 3 marker that I didn't answer :/

For the force on the electron or something in question 3 or 4, i got a very small number (something x10^-5) which seems quite small?