Physics Aftermath

nedward

mathew wrote:

Wasnt it 285 because thats where the equilibrium point is with the mass attached....

Yuh, but I took it as it'd go above that point with its kinetic energy, then come back down, and since that's its original equilibrium...


EDIT F*ck it, I'm not sure even now. Anyway, no point in post mortems, I'm going to sleep.

eZe^

mathew wrote:

I thought it was to do with the nutrino. I know Pauli discovered it, but did Fermi propose it, or something...



Find where the graph crosses the axis

I think fermi predicted that it was the anit neutrino that conserves momentum in beta decay. Well thats what I wrote down anyway!

nick23

Didnt find it too hard but it was no where near nice. Dont think ill get the A i wanted but hopefully itll b marked easy seeing as everyone thinks it was so hard!

Cipriana

I knew I shouldnt have come on here! I'm realising all the things I got wrong!! I got the focal length = 0.084, I think I even realised it was wrong at the time and just left it. I'm an idiot. Q8 what's the actual answer to (ii) and why does charge reside on the outside of a conductor? I said something about it being perpendicular. And why is silicon a semiconductor? Well I have to try and forget about it because I've chemistry tomorrow, fun.....

moggins

what did people plot against each other in the graph for focal length. was it 1/u against 1/v. but didn that give you a curved graph... why......

madnirvana

anyone got the answer for

10 a i???

i get like 11580473 m/s

microbiek

mathew wrote:

Wasnt it 285 because thats where the equilibrium point is with the mass attached....

ye...........that was really hard does any1 know what the emission line spectrum is????? is it the return wave from the star at the lower frequency???

DtotheK

the seaction a was grand i thought. didn't do Q 4(despise electricity)

The copper one was just heat gained by water = heat lost by copper (which was worked out in part (i) (i think) )

SHM question was tricky ... hoping for attempt marks but all the rest were allright ish ... had to make up a bit here and there..


Silicon is a semiconductor cause it's conductivity is between tha of a good insulator and a good conducter. and it's easy to get stoned..


I think emission line spectrum is the light from that gay star viewed through a spectro scope and it gives you a black backround and coloured lines showing different wavelengths of light emitted (or is that frequencies....)

People got the star was goin away from earth ??

carlowboy

mathew wrote:

I thought it was to do with the nutrino. I know Pauli discovered it, but did Fermi propose it, or something...

I thought it was neutrino too, but as far as I know, Fermi just named it. Pauli proposed it, other 2 men found so I thought, what's left for Fermi? So, the closest thing to Beta that I could think of was Gamma radiation.

bryanw

I didn't think that paper itself was too bad... it was a little on the difficult side and they did ask a few strange bits. I did Q1,2,3,5,7,10(b),11 and 12 (c) and (d).

Experiments were ok except I got a bit confused about how the temp. of the copper was taken. Also what was up with the graph on Q3? I couldn't find anything in any of my physics stuff about drawing a graph for the concave mirror experiment. Was completely unexpected.

I though Q5 was quite easy compared to what it can be like.

Good thing I studied the Doppler effect over the weekend for Q7. Just got a bit mixed up on the last calculation.

Q10 (b) I got the first two part but after that nothing... never studied motors or stuff like that.

Q11 was ok except what did they mean for how much energy is produced every minute? It said "300 gigawatts are produced today...." What did they mean by "today"? Was it today as in "these days" or "every day" or "this year". I just decided to take it as 300 GW in one day and then worked it out.

Q12 wasn't too bad - but I didn't get everything - didn't get the 10 marker on part (c). I'm a bit iffy about whether or not I got that half-life calculation and the last bit for (d).

microbiek

moggins wrote:

what did people plot against each other in the graph for focal length. was it 1/u against 1/v. but didn that give you a curved graph... why......

no its a line that cuts the axis at somewhere around the 8

carlowboy

Aye, got 1/f= .084

eZe^

microbiek wrote:

ye...........that was really hard does any1 know what the emission line spectrum is????? is it the return wave from the star at the lower frequency???

Its in chemistry too, its when an element is heated its electrons are excited jump to next energy level, come back down emitting a photon of definite energy which corresponds to a line on that elements emission spectrum.

carlowboy

F*** it was the neutrino. Well that's 3-6 marks down the drain.

Fobia

moggins wrote:

what did people plot against each other in the graph for focal length. was it 1/u against 1/v. but didn that give you a curved graph... why......

1/f = 1/v + 1/u. Some quick maths gives you 1/f = (v + u)/vu, invert and you have f = vu / v+u. So pop the vu on the Y axis, v + u on the X axis for your straight line through the origin. Then the slope of this is the focal length. Doubt any one of ye care any more though

madnirvana

anyone got the answer for

10 a i???

i get like 11580473 m/s

microbiek

carlowboy wrote:

Aye, got 1/f= .084

ah no i added them and said it was 16.45 or sumtin because it was already 1/u etc....i duno!!!!

JC 2K3

It was a hard paper. Q2 was a disgrace. I know I used a electricity and a fúcking Joulemeter when doing that experiment and last time I checked the syllabus, you were allowed use and learn either method.

Did all right in 1,3 and 4, but I didn't feel I did great.

Ironically, the only formula I happened to not know, T = 2pi/w, and the only area of mechanics I'm not doing for applied maths, SHM, came up. I could have persevered with Q6 and perhaps got an answer, but I decided to leave it and do other questions instead.

In the end I found there was more than enough time and I did every question bar 2(which, as I've mentioned above, had a part that's optional on the syllabus and 6(which I did half of).

Right now I've no clue how I did, probably in the B2 - A1 range, fairly happy with it.

carlowboy

where it hits the axis should be equal which is equal to 1/f

ZorbaTehZ

I was rather happy with it, if I may say so. Only think was that I only had about 10 bloody minutes to look over the test at the end.

Answered:
Q5 Very nice.

Q12 A and D, A a basic App Math question, D was nice too.

Q6 Another basic App Math, messed up the arithmetic here though, but was able to fix it at the end.

Q8 Ok question, never seen Butterfly Net Experiment on a paper though, so I'm not sure if my diagram was great. I kinda just slopped through the arithmetic here (found it hard to focus for some reason), I took the charge to be concentrated at its center. I thought comparing 4C with 5uC was kind of off-putting.

Q10A Nice question, all seen before.

--

Q1 Typical question

Q2 Typical question

Q3 Made an absolute b0llox of my graph. Couldn't remember what I was supposed to plot, so I did U against V (lol), and drew a line up where U equals V and let it equal 2f.

Pissed off didn't get enough time to look over everything properly though.

mathew

carlowboy wrote:

Aye, got 1/f= .084

Yep, got that too. It about 12cm ish

microbiek

eZe^ wrote:

Its in chemistry too, its when an element is heated its electrons are excited jump to next energy level, come back down emitting a photon of definite energy which corresponds to a line on that elements emission spectrum.

ah damn so got that wrong!!! didnt say anything bout that in the doppler chapter thats modern physics ah was real hard!!!

madnirvana

anyone got the answer for

10 a i???

i get like 11580473 m/s

DtotheK

bryanw wrote:

Q11 was ok except what did they mean for how much energy is produced every minute? It said "300 gigawatts are produced today...." What did they mean by "today"? Was it today as in "these days" or "every day" or "this year". I just decided to take it as 300 GW in one day and then worked it out.

I thought a watt was joule per second and they said today as in just in general , nowadays, 300G joules are produced per second.

I just multiplied their thing by 60 for a minute..

What did others do?????

microbiek

carlowboy wrote:

where it hits the axis should be equal which is equal to 1/f

should you not add them though like in the formula???

eZe^

microbiek wrote:

ah damn so got that wrong!!! didnt say anything bout that in the doppler chapter thats modern physics ah was real hard!!!

Ya, its the bohr model of the atom in the modern physics section!

madnirvana

DtotheK wrote:

I thought a watt was joule per second and they said today as in just in general , nowadays, 300G joules are produced per second.

I just multiplied their thing by 60 for a minute..

What did others do?????

yeah thats right.. i did same for it

eZe^

DtotheK wrote:

I thought a watt was joule per second and they said today as in just in general , nowadays, 300G joules are produced per second.

I just multiplied their thing by 60 for a minute..

What did others do?????

thats right... 60(300 X 10^9)


Whoops, wrote mega up there instead of giga!

Limerick Dude

ZorbaTehZ wrote:

I was rather happy with it, if I may say so. Only think was that I only had about 10 bloody minutes to look over the test at the end.

Answered:
Q5 Very nice.

Q12 A and D, A a basic App Math question, D was nice too.

Q6 Another basic App Math, messed up the arithmetic here though, but was able to fix it at the end.

Q8 Ok question, never seen Butterfly Net Experiment on a paper though, so I'm not sure if my diagram was great. I kinda just slopped through the arithmetic here (found it hard to focus for some reason), I took the charge to be concentrated at its center. I thought comparing 4C with 5uC was kind of off-putting.

Q10A Nice question, all seen before.

--

Q1 Typical question

Q2 Typical question

Q3 Made an absolute b0llox of my graph. Couldn't remember what I was supposed to plot, so I did U against V (lol), and drew a line up where U equals V and let it equal 2f.

Pissed off didn't get enough time to look over everything properly though.

Exactly !!! what the hell was with question 2! in the book its heated by a heating coil!!!!

Yeah was such a hard fcuking paper.....really wanted a high B but id take any C now tbh, fcuksake

DtotheK

good stuff