Physics !!!! (H)

Richard_Fonzie

Really really easy paper I thought. Some things that came up weren't expected, but were easy enough. SLH of Vaporisation probably threw some people, but the other 3 experiments were really easy. Most of the maths questions were simple too I thought, nothing too difficult to get your head around. The only come down might have been the wording in some question, that could throw people, like: "How are electrons produced in an X-ray tube?" - I'm sure lots of people just saw electron and x-ray, and went through how x-rays are created by electrons (rather than thermionic emission). All in all, an excellent test - thought I'd be scraping a B3, but fairly confident of an A1 now.

What did everyone else think?

upmeath

I'm in the same boat, got a B1 in my mock, got A1/A2 in all class tests since, and I'm nearly sure of my A1 after today. Easiest paper since they introduced the new syllabus. Finished my 3A's and 5B's by 12.05 so i went back in for A2 and B10. Nothing could knock me.

Señor Juárez

What a simplistic paper. Messed up a couple of questions, and left out the "at constant temperature" from the end of Boyle's Law. But then again, I did two extra questions, so all should be well.

*Angel*

Experiments were very easy, I couldn't have asked for better, however the experiment to verify the principle of conservation of momentum was obviously talking about a different experiment to the one we had carried out (however not much different). I did experiments 1,2 & 3.

Q5 I got all parts (apart 2nd j part)

Q6 I ignored at first because I hadn't revised circ motion... I got it all however I just realised that for v, I put v=2(pi) instead of v=2(pi)r, stupid mistake but hopefully not a huge amount of marks.

Q7 very easy, but I hate describing experiments, I'm usually confusing when I'm trying to explain things.

Q10 I started with 1st in section B, I thought electric field strength is the same as electric field intensity so that's how I started the question, however I decided that I was wrong, so I didn't finish the question (me stupid), doesn't matter it was a spare.

Q11 I never do the article question, I generally just don't like it. But the questions were very straightforward, I was kinda disappointed with their lack of interesting questions but very easy.

Q12 I did parts 'a' and 'c', found them grand.



Overall I'm very happy with the paper, I was a little worried with how easy it was cos usually I have no spare time, but I was finished early and was wondering if I had skipped a question or something.

OTliddy

That was onimously simple. The experiments were not exactly what were predicted, but the equestions on them were easy. I did all the experiments.
Only thing was I couldnt get the difference in resistance USING THE GRAPH. I did it mathematically instead.

5-easy, got 9 of them done
6-very easy
7-very easy
9-easy
10-okay, the only catch was the very last bit, i forgot that it was a vector.
12-did a b and c...all easy.

I heard that question 11(a) was simple aswell.
My answers were the same as the rest of my class to the sums. Overall, i'd say i got at least 95%.
That paper will be marked very hard; lots of people will be getting A1s with the current marking scheme.

*Angel*

Yeah I was kinda thinking that, they can't give everyone As.

stevoxbx

Does that mean it will work to my advantage that i got around a C3? Like if they make the marking scheme harder will it take down only the A1 and A2 grades or all grades?

Waltons

Lovely paper overall! Did 1,2 and 3 in Section A and 5,6,7,11(a), and 12(a & d). Only had problems with 7 because I hadn't looked over much stuff about waves but the rest were very easy

upmeath

I personally think that provided constants and figures should be given at the inroductory stage in a question...when I was asked for the radius of the satellite's orbit of Saturn I stalled for five minutes because the planet's mass was in little scuttery type at the very end of the question. It should be in italicised bold type after the introduction. Thank you.

*Angel*

I'd say it'll effect everyone, the marking scheme will be discussed and changed for everyone. I think.

ozt9vdujny3srf

effects all grades, they cant mark wrong what you got right though, its mostly cutbacks in attempt marks and more finicky marking of definitions. Its marked to a curve.

Ishmael

The easier the paper, the harder they're going to mark it! :eek: :eek:

Edit: Damn taking my time writing posts!! :mad: , nevermind!!!

*Angel*

upmeath wrote:

I personally think that provided constants and figures should be given at the inroductory stage in a question...when I was asked for the radius of the satellite's orbit of Saturn I stalled for five minutes because the planet's mass was in little scuttery type at the very end of the question. It should be in italicised bold type after the introduction. Thank you.

In fairness, they've always put the necessary given values at the bottom of the question, however yes it should never be like that.

sixdraw

I thought it was a lovely paper aswell but I'd say there's probably enough tricky parts to seperate the A's. the frequency of the radio waves changing , Doppler effect. Thank god that came to me in the exam.

Richard_Fonzie

^^^
Were they looking for the idea that the satellite in its orbit will be moving towards earth, and away from earth as it goes around its period? Or that both Saturn and Earth have different velocities about the sun, hence the distance between the two (and the satellite as a result) would be constantly changing? Or both?

I screwed up a little on 3 (snell's law), got 2.17 instead of 1.3-1.5 for the refractive index. Couldn't figure out what I'd done wrong either. Everything on the right axis, line even went through the origin. Had slope formula down and 'sini/sinr=n', so hopefully they dont punish me too much...

Richard_Fonzie

Also for 10.) - Describe experiment to show eletric field pattern, would water + acid (to provide h+ & oh- ions), circuit + electrodes, and semolina be what they were looking for?

crowl

easy enough paper, i dont think they will mark it so hard though, id say a people who dont understand the subject still didnt do great

JackKelly

very good paper. very happy. Only thing i couldnt get was the last bit in A4.If it's right, its right. If you deserve an A1, you'll get an a1

sci0x

It was a bit too easy. I find every in every leaving cert exam this year, its the easiest year in most of my subjects. Hope the same will happen for Chemistry 2moro

sixdraw

ya the trend better be the same with chemistry. I have to get a B tomorrow for my course

Doctor D-Man

Grand paper altogether. Some parts were a bit tricky but the most I lost is about 5% and thats marking myself hard.

SECTION A
1. Simple exp. even though it wasnt predicted. I think they were on about the one using ticker timer whereas we used the air track. I just adapted the questions a bit to suit our exp. Surely they cant take marks for that though.

2. didnt do it. not too bad all the same

3. Snells Law - as predicted. No problems here. I was actually able to guess all the questions before I even read them. Nothing new whatsoever. I think its an exact copy of a sample i saw somewhere, could be wrong though.

4. Fine out. Ended up repeating myself a small bit at the end when they asked why I is not prop to pd and the reason the resistance changes. Might not have given all the info required as it was worth 18marks

5. answered all the questions without a bother. full marks here

6. Really basic stuff. The derivation of period was on. Glad to see that. Might have got some figures wrong in calculations. The second calculation (time taken for signal to reach earth) must have been a mistake. It was in no way related to the first part and hence you were given 9 marks for a one-line calculation. Have I missed something here??

7. No problems. I really liked the fact that they asked the too easy wave exps. easy 21 marks there.

8. done this as an extra question coz i didnt really put muxh effort into radiation. first parts were fine. didn't know how 2 demonstrate ionisation. also couldnt do calculation (iii) - probably very easy too i suppose

9. skipped it. dont know why but i always seem to make mistakes in elec. questions so i decided to leave it out

10. Coulombs law. Nothing too difficult - was highly tipped to come up also. I left out a bit at the end though

11. skipped it. Nothing hard there though. I suppose I shouldve done that instead of 10.

12 (a) took some logical thinking - think i got it all right
(b) skipped it
(c) easy out
(d) highly tipped to come up - nothing too hard there either

Overall I'd say I have to get at least an A2. Considering the easiness of the whole paper, I doubt I'll be up for an A1. They will probably be given to candidates who have given the most detail in their answers

Johnerr

i did'ent do much study, i thought i was alright, hopefully i passed it, (only got 23%) in the mocks, and how do ya get the refractive index of the glass block is it slope of graph?

Anyone wana throw up some answers for Section A 1,2,3

Section B
5,6,7,11b,12a,d

sixdraw

you know on ques one about the 0.2s what did ye write?

Richard_Fonzie

That the ticker tape timer operates at a certain frequency (probably 50hz), mean every 1/50th (or .02 seconds) it makes a hole in the tape. Hence if the distance measured between two points is x, then the distance travelled by the trolley is this value x, and hence it takes .02 seconds to travel this distance (since it took .02 seconds for the two ticks).

*Angel*

Doctor D-Man wrote:

6. .................... The second calculation (time taken for signal to reach earth) must have been a mistake. It was in no way related to the first part and hence you were given 9 marks for a one-line calculation. Have I missed something here??

Yeah it seemed to come out of nowhere...

sixdraw

if you used the air track though whats the story then, as it is an option is it not which way you do it

*Angel*

Richard_Fonzie wrote:

That the ticker tape timer operates at a certain frequency (probably 50hz), mean every 1/50th (or .02 seconds) it makes a hole in the tape. Hence if the distance measured between two points is x, then the distance travelled by the trolley is this value x, and hence it takes .02 seconds to travel this distance (since it took .02 seconds for the two ticks).

For that experiment, I wrote about the 2 gliders on the air-track, with the light gates measuring the times. Not what they were talking about cos the times would not be the same, but I kinda worked around it.

sixdraw

ya i tried that, if its an option in the syllabus they'll have to give the marks.i said you know the distance between the 1st gate and the second rider so you get the speed from the 1st gate and divide the distance by it to get 0.2s

rasher_b2

Doctor D-Man wrote:

4. Fine out. Ended up repeating myself a small bit at the end when they asked why I is not prop to pd and the reason the resistance changes. Might not have given all the info required as it was worth 18marks

I found I was writing the same answer too

Johnerr wrote:

i did'ent do much study, i thought i was alright, hopefully i passed it, (only got 23%) in the mocks, and how do ya get the refractive index of the glass block is it slope of graph?

Yeah, get the slope of the line from your graph.


I thought the paper was alright too so hopefully i can get a decent mark in it.

Webmonkey

A Pure dos of a physics paper. A definate A1 finally, something in this LC.

StupidLikeAFox

I jus have a little question about the snells law experiment

What i did was draw the graph and all correct, then took two points of the x-axis, drew a line up (as you can see, and used the corresponding y-values to calculate the slope using the formula. I also put in the the slope of the line would give sin i/sin r. Thats what your supposed to do yeah?

On the whole i was delighted with my paper, considering i did no study at all. I worked it out and got a C1 or B3 or thereabouts, which was nice.

vote4pedro

Very fair paper, but I'm annoyed at myself for making stupid mistakes (wrote Photoelectric instead of Thermionic effect in q.5 :mad: ) Was stumped by height of the ball bouncing in q 12. a, and I also messed up the first 3 questions of Particle Physics bit but still should have got a B3 at least. Any Physics, ahem, 'enthusiasts' want to go through the paper again and write up results to maths probs/calculations?

stevoxbx

I just found 1value for sin i and sinr from the graph and put them into the thingy sin i/sin r.

Sandals

Did anyone else think that the maths questions were incredibly easy, in comparison to book and other years?


Even the first question in q.5 on pressure was so easy i didnt fu=igure it out for while it was just force/area as in from junior cert, i just remembered my teacher describing it in terms of a woman wearing stilletos!

The question 6 was much easier than normal circular motion questions!
I am glad that my one gues "The doppler effect"for the last part appears to be right

Q.7 I didnt like although it was easy 'cause i mixed up the youngs slits in the diagram for a diffraction grating!

q.8 was a very easy radioactivity question, the maths at the end was a joke
for ionisation i said
Where particles become charged into ions and accelerate into more ions causing the ionisation of more particles
is that in anyway right?

q.9 was fine except for the last 2 q's i bluffed my way through them getting attempt marks,
1. I just drew the graph of res. vs. temp and said they were not proportional
2. I said the total r has gone down v=ixr therefore v has gone down


q.10
i think i did well, for the 2nd last q was it e=q/d

and for the last one f=q1q2/4pied^2?

q.11(a)
was simple!
except for circular acellerators i said
(a)they can have accelerate to higher velocitys
(b) they can cause particles to collide
and (c) they are safer?? are any of those right??

q.12 i did a c and d, all ok b was too easy to be true!

Overall handy out I thought

colhol wrote:

What i did was draw the graph and all correct, then took two points of the x-axis, drew a line up (as you can see, and used the corresponding y-values to calculate the slope using the formula. I also put in the the slope of the line would give sin i/sin r. Thats what your supposed to do yeah?

yes that is perfect., most people dont do it that way though!
was your answer near 1.5?

sci0x

Thats the right way to do it, find the slope of the line to get the refractive index. I got 1.45

stevoxbx

can it be done by just taking th sin i value and the sin r value and put them over each other to get 1.5?

CoffeeFreak

It was a really easy paper...I think the easiest of all my exams so far...weird. I hope I get an A1

Richard_Fonzie

q.11(a)
was simple!
except for circular acellerators i said
(a)they can have accelerate to higher velocitys
(b) they can cause particles to collide
and (c) they are safer?? are any of those right??

I'm not sure if that's right.
a) might be correct, because particles can go around once, and then go around again (increasing speed)? But I think that for any circular acclerator, you could match it with a linear one by just making the linear one longer and increasing the voltage across it.
b) was something like what I had. I reasoned that in the linear, if two particles miss each other, they can't have another chance to collide without starting the whole thing again (i.e. you'd need to accelerate more particles). Whereas in the circular accelerator if they miss, the same two particles can just go around again and have another go.

Richard_Fonzie

can it be done by just taking th sin i value and the sin r value and put them over each other to get 1.5?

Yeah, but you'll probably lose marks, because I think you're supposed to use the graph (and hence the average of ALL the values) to find it.

*Angel*

stevoxbx wrote:

can it be done by just taking th sin i value and the sin r value and put them over each other to get 1.5?

It says 'from your graph'.

Richard_Fonzie

Yes but when you use the graph to find it, you typically find the slope of the graph, and in this case the slope is sini/sinr=n. If you didn't find the slope accurately, then you could have just picked a sini & a sinr value from the table and found n without using the graph at all.

edit: nevermind

Moira

overall very happy! exactly like my pre!
q1 conservation of momentum, great that we didnt have to describe the big long experiment cos thats just wicked long. just hope my calculations were right.

q2. please let my maths be right, had to do it so many times cos each time forgot to convert something in standard international units. 24 marks is alot gone if its wrong.

q3. lovely, knew it had to come up.

q4. didnt do it cos the end of it looked a bit dodgey for me.

q5. best ever, such a beauty.

q6. nice, good to see that keplers law coming up but couldnt think of doppler effect but did say something about speed if i remember right.

q7. nice, everything except the last bit cos we had never written that exp up prop.

q.8 didnt do, hate half life and that stuff

q.9 didnt do, but looked ok

q10. when i saw this i panicked, like where was the option q. but did this, was grand, again calculations i wouldnt b the best at.

q11a thought it was really unfair to mix up the theme q and the option q cos i find the theme q a bitch anyway, but did it away turned out alright, anyone the answer to part iii?? prob simple but couldnt think.
b didnt do that option

q12. really nice part a, and in b is it ok to write down the formula of magnetic flux?? just couldnt think of the definition.

prob will mark it harder now but still they cant change it that much cos well i usually base my choice of q on the distribution of mark, they cant just throw that guide out the window. id say it will be for things like forgetting units we'll be shafted for etc.

nobodythere

This is gonna be one HELL of a marking scheme

Sandals

Moira wrote:

q11a thought it was really unfair to mix up the theme q and the option q cos i find the theme q a bitch anyway, but did it away turned out alright, anyone the answer to part iii??

I just GUESSED
because neutrons dont have a charge - are stable

OTliddy

Richard_Fonzie wrote:

(and hence the average of ALL the values) to find it.

No. Pick two values, fairly far apart and use the slope formula to get the resistance, thats if u have sin i on the y-axis. Not sure if picking the point (0,0) would count....they could use it as an excuse to harden the marking scheme.

Here are some answers I got that I noted down:
Section A
Q2: Latent heat=2.285x10^6
Q3: Refractive index=1.44
Q4: change in resistance=17(or 19).69cant read if i wrote 17 or 19, mite b 17.

Section B
5.(d) 15 cm
9.(i) 600 ohms (ii) 4 milliamps i think
10(last bit) 7.153x10^-13
12(a) kinetic energy=17.934 J new height=2.03 m
12(c) 384.6 Hz 769.2Hz
12(b)(i)0.01 Wb
(ii)0.05 V

Other notes
For the radio signal part of Q6, there are prob 3 points going for c=f(lambda)
3 for substition, and 3 for answer.
For the last part, i'd say you'd get 5 marks if u just wrote down "doppler effect"

Webmonkey

Hmm I got the height in 12a as 1.02m i think asfar as i remember.
Kenetic Energy lost = Potential energy gained.
Ep = mgh so lost 6 Jules wasn't it?
6 = (.6)(9.8)x
x = 6/5.88 = 1.02m?

I probably took wrong figures knowing me. I dont' have the paper here so please tell me im right :S

OTliddy

Webmonkey wrote:

Hmm I got the height in 12a as 1.02m i think asfar as i remember.
Kenetic Energy lost = Potential energy gained.
Ep = mgh so lost 6 Jules wasn't it?
6 = (.6)(9.8)x
x = 6/5.88 = 1.02m?

I probably took wrong figures knowing me. I dont' have the paper here so please tell me im right :S

U got the right figures. my method was different(and much longer), but ur method is right aswell.I said the potential energy is the old energy minus the loss in energy, thus:
Ep=17.934-6
11.934=5.88x
x=2.02 m

If there was no loss in energy, the ball would bounce back up 3.05 m again, so i figured that the height decrease must be proportioanal to the energy loss

Sandals

What is ionisation?

defiantshrimp

Sandals wrote:

What is ionisation?

Far as I know it is when a neutral molecule/element/atom is ionised (in other words given a charge) when electrons are knocked out of its orbit. Usually by radiation (alpha, beta or gamma) or other ions.

StupidLikeAFox

Sandals wrote:

yes that is perfect., most people dont do it that way though!
was your answer near 1.5?

1.5 on the button baby! Happy days!

Sandals

ColHol wrote:

1.5 on the button baby! Happy days!

ok thats good!