MAY11 Physics SL Papers 1-3 Timezone 1

[CecilyT]

So what did everyone think of the Physics exam?

I personally felt that Paper 1 was pretty simple, I finished and had 25 minutes left to check it over. Paper 2 I found more difficult. I didn't really like the selection of section B questions; I ended up choosing B2 (the one about mechanics/thermal and then nuclear) but I messed up pretty horridly on binding energy per nucleon because I was rushing and didn't have enough time to go back and fix it. For Paper 3 my school covered options B and G (nuclear and EMR), and in comparison to the practice tests I had tried I thought it was not too bad, although I am glad I reviewed the night before.

[ceeN]

So what did everyone think of the Physics exam?

I personally felt that Paper 1 was pretty simple, I finished and had 25 minutes left to check it over. Paper 2 I found more difficult. I didn't really like the selection of section B questions; I ended up choosing B2 (the one about mechanics/thermal and then nuclear) but I messed up pretty horridly on binding energy per nucleon because I was rushing and didn't have enough time to go back and fix it. For Paper 3 my school covered options B and G (nuclear and EMR), and in comparison to the practice tests I had tried I thought it was not too bad, although I am glad I reviewed the night before.

I thought paper 1 was pretty simple as well. Paper 2 was fine I think, I did the same question as u did and I think I did fine (by the 2010 grade boundaries a 7 on paper 2 was 29 out of 50,so let's hope it stays the same). For paper 3 my school chose options A and E (Waves and Astrophysics) both of them were very easy, some repeating questions from past year,so I didn't have much problem with them.

[Drake Glau]

Paper1 was amazing in my opinion. Pretty straight forward with minimal trick questions

Paper2 was iffy. Some of them I just blanked out on what to do but the part B was ok. I chose the one with nuclear and simple harmonic motion I think. The nuclear part was easy and the motion was pretty good, but I'm not that great at it anyway =/

Paper3 we did astrophysics and electromagnetic waves. The only problem with astrophysics was the one where they gave us the apparent brightness of the sun and Star A and all that stuff. I knew how to do it using the b=L/4pid^2 equation but my calculator was giving me overflow numbers because apparently that was giving me distance in meters and I mean...800pc...is WAY to big to fit on a calculator in meters. The electromagnetic waves question that killed me was the last one that involved Na light and the different orders and deffration gratings. We ran out of time and never went over this except for 3 people who did a lab over it which I wasn't part of. So right off the bat I'm down 9 points on paper3

[ceeN]

Paper1 was amazing in my opinion. Pretty straight forward with minimal trick questions

Paper2 was iffy. Some of them I just blanked out on what to do but the part B was ok. I chose the one with nuclear and simple harmonic motion I think. The nuclear part was easy and the motion was pretty good, but I'm not that great at it anyway =/

Paper3 we did astrophysics and electromagnetic waves. The only problem with astrophysics was the one where they gave us the apparent brightness of the sun and Star A and all that stuff. I knew how to do it using the b=L/4pid^2 equation but my calculator was giving me overflow numbers because apparently that was giving me distance in meters and I mean...800pc...is WAY to big to fit on a calculator in meters. The electromagnetic waves question that killed me was the last one that involved Na light and the different orders and deffration gratings. We ran out of time and never went over this except for 3 people who did a lab over it which I wasn't part of. So right off the bat I'm down 9 points on paper3

Well what u had to do in the apparent birghtness question is to plug in 1 AU for the distance from the sun to the earth, and then find the distance from the earth to star A in AU units, then u convert from AU to pc and u get 800pc. U probably didn't use the fact that the distance from the sun to earth is 1AU so u had an error or something.

I think a simmilar question was on a past paper from 2009 if I'm not wrong cuz we did almost the same question in class.

Edited May 14, 2011 by ceeN

[Drake Glau]

Paper1 was amazing in my opinion. Pretty straight forward with minimal trick questions

Paper2 was iffy. Some of them I just blanked out on what to do but the part B was ok. I chose the one with nuclear and simple harmonic motion I think. The nuclear part was easy and the motion was pretty good, but I'm not that great at it anyway =/

Paper3 we did astrophysics and electromagnetic waves. The only problem with astrophysics was the one where they gave us the apparent brightness of the sun and Star A and all that stuff. I knew how to do it using the b=L/4pid^2 equation but my calculator was giving me overflow numbers because apparently that was giving me distance in meters and I mean...800pc...is WAY to big to fit on a calculator in meters. The electromagnetic waves question that killed me was the last one that involved Na light and the different orders and deffration gratings. We ran out of time and never went over this except for 3 people who did a lab over it which I wasn't part of. So right off the bat I'm down 9 points on paper3

Well what u had to do in the apparent birghtness question is to plug in 1 AU for the distance from the sun to the earth, and then find the distance from the earth to star A in AU units, then u convert from AU to pc and u get 800pc. U probably didn't use the fact that the distance from the sun to earth is 1AU so u had an error or something.

I think a simmilar question was on a past paper from 2009 if I'm not wrong cuz we did almost the same question in class.

That would make tons of since =/ Crud. Oh well, it was my 7th IB class so it won't affect anything, but it does answer my confusion of why they gave us the sun's brightness too

So you're saying I should have used the equation twice so I would end up with AUs instead of meters and then just convert?...ugh...

[ceeN]

Paper1 was amazing in my opinion. Pretty straight forward with minimal trick questions

Paper2 was iffy. Some of them I just blanked out on what to do but the part B was ok. I chose the one with nuclear and simple harmonic motion I think. The nuclear part was easy and the motion was pretty good, but I'm not that great at it anyway =/

Paper3 we did astrophysics and electromagnetic waves. The only problem with astrophysics was the one where they gave us the apparent brightness of the sun and Star A and all that stuff. I knew how to do it using the b=L/4pid^2 equation but my calculator was giving me overflow numbers because apparently that was giving me distance in meters and I mean...800pc...is WAY to big to fit on a calculator in meters. The electromagnetic waves question that killed me was the last one that involved Na light and the different orders and deffration gratings. We ran out of time and never went over this except for 3 people who did a lab over it which I wasn't part of. So right off the bat I'm down 9 points on paper3

Well what u had to do in the apparent birghtness question is to plug in 1 AU for the distance from the sun to the earth, and then find the distance from the earth to star A in AU units, then u convert from AU to pc and u get 800pc. U probably didn't use the fact that the distance from the sun to earth is 1AU so u had an error or something.

I think a simmilar question was on a past paper from 2009 if I'm not wrong cuz we did almost the same question in class.

That would make tons of since =/ Crud. Oh well, it was my 7th IB class so it won't affect anything, but it does answer my confusion of why they gave us the sun's brightness too

So you're saying I should have used the equation twice so I would end up with AUs instead of meters and then just convert?...ugh...

Basically u should have used the formula b=L/4pi*d^2 and make a ratio b(A)/b(S), where b(A) is apparent brightness of star A and b(S) is apparent brightness of the sun, then from the graph u should have taken L(A) (The sun's L is 1 so L(A)/L(Sun)=L(A)) Therefore u'd get that d(A)^2/d(S)^2= L(A)*b(S)/b(A). and then u know that the mean distance fom the sun to earth is 1 AU. therefore u'll get D(A)=sqrt(L(A)*b(S)/b(A)). This answer will be the distance from star A to earth in AU, and when u convert to pc u get 800. Hope that helps .

[Drake Glau]

Gah! I was looking for a ratio relation between the b and d and I guess I just ran out of time before I got there =/ But yea, that helps ease the confusion Thanks!

[ceeN]

Gah! I was looking for a ratio relation between the b and d and I guess I just ran out of time before I got there =/ But yea, that helps ease the confusion Thanks!

lol you are very welcome

[Ben92]

how much did you get the star's, Bertelgusen's(or something like that), temperature to be?

[CecilyT]

Something interesting about Paper 3:

One of the questions in option G (Electromagnetic Radiation) asked the approximate wavelength of visible light. When I had finished the paper and checked it over and everything I was bored so I read through some of the other options, and in option A they tell you straight up that the the average wavelength of visible light is 550 nm. I guess they don't expect someone to be doing both A and G or something. But I thought it was quite hilarious and so added it to the end of my answer for the question in G. I wonder if they will notice.

[kasandude]

Paper 1 was gift from the IB gods, pure win IMO. I'm expecting myself to be well in level 7 territory for that one. Paper 2 was a bit worse, but only because I mixed up the answer boxes in the beginning and had to rewrite the question, which left me little time for the section B, which was OK, but could have been a lot better (the bus question was idiotically easy). Still, probably level 5-6 from Paper 2.

Paper 3 made me want to cry. I forgot about the options and revised the day beforehand as well as the morning of. Forgot the Reighleg's thing completely, so sight and wave phenomenon was a fail. Astrophysics could be decent, but I couldn't, for the life in me, figure out what they meant by 'solar radii.' Someone later told me that it was the sun's radius... which I thought deserved a big fat "D'oh!" Paper 3's probably a low 4, honestly.

I guess I could be hovering around level 5/6 for the exams. Hope that internal assessment will pull me up a bit...

[Drake Glau]

Something interesting about Paper 3:

One of the questions in option G (Electromagnetic Radiation) asked the approximate wavelength of visible light. When I had finished the paper and checked it over and everything I was bored so I read through some of the other options, and in option A they tell you straight up that the the average wavelength of visible light is 550 nm. I guess they don't expect someone to be doing both A and G or something. But I thought it was quite hilarious and so added it to the end of my answer for the question in G. I wonder if they will notice.

I think the question actually asked for the approximate range. They were looking for 400-700nm

But yea, that is rather funny that IB wouldn't catch something like that. Knowing the average was taken by a min and max value you could quickly figure out a min-max range that averages to 550nm

[CecilyT]

Something interesting about Paper 3:

One of the questions in option G (Electromagnetic Radiation) asked the approximate wavelength of visible light. When I had finished the paper and checked it over and everything I was bored so I read through some of the other options, and in option A they tell you straight up that the the average wavelength of visible light is 550 nm. I guess they don't expect someone to be doing both A and G or something. But I thought it was quite hilarious and so added it to the end of my answer for the question in G. I wonder if they will notice.

I think the question actually asked for the approximate range. They were looking for 400-700nm

But yea, that is rather funny that IB wouldn't catch something like that. Knowing the average was taken by a min and max value you could quickly figure out a min-max range that averages to 550nm

Yeah, well it is a good thing I put down 400-700 nm then! I just tagged the last bit on at the very end. "Incidentally, the average wavelength of visible light is 550 nm." or something along those lines.

[Drake Glau]

Something interesting about Paper 3:

One of the questions in option G (Electromagnetic Radiation) asked the approximate wavelength of visible light. When I had finished the paper and checked it over and everything I was bored so I read through some of the other options, and in option A they tell you straight up that the the average wavelength of visible light is 550 nm. I guess they don't expect someone to be doing both A and G or something. But I thought it was quite hilarious and so added it to the end of my answer for the question in G. I wonder if they will notice.

I think the question actually asked for the approximate range. They were looking for 400-700nm

But yea, that is rather funny that IB wouldn't catch something like that. Knowing the average was taken by a min and max value you could quickly figure out a min-max range that averages to 550nm

Yeah, well it is a good thing I put down 400-700 nm then! I just tagged the last bit on at the very end. "Incidentally, the average wavelength of visible light is 550 nm." or something along those lines.

Hahah good! Free points are always welcome. Like astrophysics! Order these 4 planets in increasing diameter. Now order them in increasing orbit diameter. YAY!

[MoneyWinker]

TZ1

I found Paper 1 easy (but I know I got at least 3 questions wrong for SURE - probably more)

Paper 2: I did B1, it was easy except for the VERY last two questions. It asked for the pattern for the longitudinal wave and to mark the rarefraction (lost 3 marks + 1 mark). Other than that I think OK in the B2 section, maybe a few stupid calculation errors. Section A3, I made the stupidest mistake! Lost 2+2 marks (equilibrium circular motion). Also, I messed up on finding the unit of the slope, my friends told me that "n" doesn't have units. I put m^2 per n, which is wrong but it's only worth 1 mark. So about 9 marks cut off for Paper 2 FOR SURE.

Paper 3: I did Option A and B. It was relatively easy compared to Paper 2. In Option A, was the standing wave an open end + closed end or was it 2 open ends? I probably lost 3 marks in that section. In the second option, I answered all the questions but I am not sure if my points will be on the marking scheme.

[ceeN]

TZ1

I found Paper 1 easy (but I know I got at least 3 questions wrong for SURE - probably more)

Paper 2: I did B1, it was easy except for the VERY last two questions. It asked for the pattern for the longitudinal wave and to mark the rarefraction (lost 3 marks + 1 mark). Other than that I think OK in the B2 section, maybe a few stupid calculation errors. Section A3, I made the stupidest mistake! Lost 2+2 marks (equilibrium circular motion). Also, I messed up on finding the unit of the slope, my friends told me that "n" doesn't have units. I put m^2 per n, which is wrong but it's only worth 1 mark. So about 9 marks cut off for Paper 2 FOR SURE.

Paper 3: I did Option A and B. It was relatively easy compared to Paper 2. In Option A, was the standing wave an open end + closed end or was it 2 open ends? I probably lost 3 marks in that section. In the second option, I answered all the questions but I am not sure if my points will be on the marking scheme.

If I remember correctly, it said in the question an open-open pipe. (I'm almost 100% about it)

[MoneyWinker]

TZ1

I found Paper 1 easy (but I know I got at least 3 questions wrong for SURE - probably more)

Paper 2: I did B1, it was easy except for the VERY last two questions. It asked for the pattern for the longitudinal wave and to mark the rarefraction (lost 3 marks + 1 mark). Other than that I think OK in the B2 section, maybe a few stupid calculation errors. Section A3, I made the stupidest mistake! Lost 2+2 marks (equilibrium circular motion). Also, I messed up on finding the unit of the slope, my friends told me that "n" doesn't have units. I put m^2 per n, which is wrong but it's only worth 1 mark. So about 9 marks cut off for Paper 2 FOR SURE.

Paper 3: I did Option A and B. It was relatively easy compared to Paper 2. In Option A, was the standing wave an open end + closed end or was it 2 open ends? I probably lost 3 marks in that section. In the second option, I answered all the questions but I am not sure if my points will be on the marking scheme.

If I remember correctly, it said in the question an open-open pipe. (I'm almost 100% about it)

I read that too but I thought it would be an open-closed standing wave (wavelength = 4L/n) because part of the tube would be submerged under water. That means that the tube should act like an open-closed end but I am not sure if that is the correct answer... could someone clarify this, thanks.