!! Physics 2015 ... predictions, guesses and discussion

lala0815

I am so nervous ... i also have accounting that day and chemistry on tuesday !!

Troxck

MmmPancakes wrote: »

Do you have to know the particles under the particle headings like Leptons, Mesons and Baryons?

Yeah, I have this little chart made out but I can't attach it from my phone, sorry!

If you're desperate I can email it to you but my writing is terrible and it's not great really...

MmmPancakes

Troxck wrote: »

Yeah, I have this little chart made out but I can't attach it from my phone, sorry!

If you're desperate I can email it to you but my writing is terrible and it's not great really...

Nah it's fine, I'll learn them, just wasn't sure if we had to.

Elemonator

What are people predicting for Section A?

Dianabluex

Elemonator wrote: »

What are people predicting for Section A?

measure the wavelength of monochromatic light
heat experiment
variation current with potential difference
acceleration due to gravity 9 free fall
resistivity of a nichrome wire
fundamental frequency of a stretched string with tension
focal length
one guy told me snells law but i aint sure came up last year
hopeful four them will come up

Cr4pSnip3r

Elemonator wrote: »

What are people predicting for Section A?

F=ma experiment, monochromatic light, specific latent heat of vaporisation of water and the investigation of the variation of the current I with potential difference V

Elemonator

Dianabluex wrote: »

measure the wavelength of monochromatic light
heat experiment
variation current with potential difference
acceleration due to gravity 9 free fall
resistivity of a nichrome wire
fundamental frequency of a stretched string with tension
focal length
one guy told me snells law but i aint sure came up last year
hopeful four them will come up

Just went over gravity, feel like a champ

Elemonator

Anyone know where the questions are in the exam papers for experiments Resistivity of Wire, Monochromatic Light, Heat by vaporisation of water, Current/Potential Difference, Frequency of stretched string, Focal length, shells law and f=ma? My chapters are messed up?!

evanbeaulieu

why do ppl think that variation of current with pd is coming up? it came up 3 times in a row? like variation of resistance and metallic conductor looks more like what will come up?

Dianabluex

evanbeaulieu wrote: »

why do ppl think that variation of current with pd is coming up? it came up 3 times in a row? like variation of resistance and metallic conductor looks more like what will come up?

variation current with potential of filament bulb only came once which is wayyyy back in 2005 so i say better watch out for it

randylonghorn

Cr4pSnip3r wrote: »

My mock would agree with you, Barry.

Never rely too much on mocks though; they usually do try to make a best guess as to what might be likely to come up that year, but in reality they have no more clue than anyone else.

Troxck

randylonghorn wrote: »

Never rely too much on mocks though; they usually do try to make a best guess as to what might be likely to come up that year, but in reality they have no more clue than anyone else.

Our teacher said that the Mock companies try to make the best predictions so that the teachers will buy from them again the following year. Makes sense, they're just businesses at the same time.

I did the 2014 Mock from both DEBS and Examcraft and neither were similar to the actual 2014 Paper!

randylonghorn

Troxck wrote: »

Our teacher said that the Mock companies try to make the best predictions so that the teachers will buy from them again the following year. Makes sense, they're just businesses at the same time.

Sure, but they're still only "best guess", like; they have absolutely no inside information. Nobody has, though to listen to some, you'd swear they were sleeping with every question-setter the SEC use! :pac:

Cr4pSnip3r

Troxck wrote: »

Can someone help me with regards to the coplanar forces experiment? How do you determine whether a force is clockwise or anticlockwise? I thought I was doing it right but then In went to the marking scheme and it's the exact opposite to what I said. If I said it was clockwise, the marking scheme said it is anticlockwise and so on.

What am I doing wrong?

Well, clockwise would be pushing up on the left, down on the right, no? So like, left hand side weights would be anti-clockwise and right hand side weights would be clockwise?

Cr4pSnip3r

Troxck wrote: »

Okay for example from 2007 HL.

Position on metre stick/cm: 11.5
Magnitude of force/N: 2.0
Direction of force: down

I took this to be anticlockwise, the marking scheme said clockwise.

What am I doing wrong?

It appears the ruler may be being held at 0 rather than at 50 and so any forces act accordingly?

evanbeaulieu

usually the forces up have to be equal to the forces down, and if u look at the question u have 3 anticlockwise and 2 clockwise, so the ruler has to be moving clockwise for the forces to be equal.

Bartekm57

acceleration due to gravity
newtons second law
the latent heat of vaporisation
calculate the specific heat capacity of water or copper
the sonometer
measure the wave lenght of mochromatic light using a spectrometer
find the focal length of converging lens
the resistivity of nichrome

lala0815

for the graphs does it matter what side the variables are ...or is it just what you control on the x axis ?

Troxck

lala0815 wrote: »

for the graphs does it matter what side the variables are ...or is it just what you control on the x axis ?

It is convention that whatever goes onto the X-axis was the controlled variable. Also, working out slop has implications. In the F proportional to a formula, we controlled F so that goes onto the X, however to show the F proportional to a, we need to get the slope and invert it.

Broseph

lala0815 wrote: »

for the graphs does it matter what side the variables are ...or is it just what you control on the x axis ?

Try to match up the formula used with the equation y=mx + c
Say period of a pendulum formula: T = 2(pi) root(length/gravity)
Y= Period and X= root length therefore slope= 2(pi)/root(g) yeah?

quartzx7

If you had time to do an extra question should you do an experiment question or one from section b? Or maybe an extra part in the q12?

Broseph

quartzx7 wrote: »

If you had time to do an extra question should you do an experiment question or one from section b? Or maybe an extra part in the q12?

Pick out the question which is your weakest and do an extra question from that question. It's unlikely to be q12 because each part is worth only half of the marks. I'd restrict it to a new experiment question or from question 5 to 11.

DarraghF197

I'll probably do six Section B questions and an extra Q12, unless I feel the short questions would be a waste of time. I'll do four experiments if I get lucky and a resistance question comes up for electricity. Don't really know if time will be a problem yet.

Broseph

DarraghF197 wrote: »

I'll probably do six Section B questions and an extra Q12, unless I feel the short q

Will do the 4 experiment questions, Q5, Q12, and the nicer questions of the rest adding up to one extra question all going well.
Edit: I found time to be a problem in the pre just got the exact amount of questions done but ended up with 89%. I do think that if I'd worked a bit faster there would definitely have been time for one extra, can't see two happening though.

DarraghF197

Broseph wrote: »

Will do the 4 experiment questions, Q5, Q12, and the nicer questions of the rest adding up to one extra question all going well.
Edit: I found time to be a problem in the pre just got the exact amount of questions done but ended up with 89%. I do think that if I'd worked a bit faster there would definitely have been time for one extra, can't see two happening though.

I did a quick calculation there that leaves a good bit of time. I think it's quite manageable to get an extra experiment, an extra Section B question and a Q12 part in the time given. We could take 16 minutes per experiment, and then 16 minutes per long question, 25 minutes 12, and 10 for the short questions.

Sorry, my phone keeps breaking down, really frustrating lol

sfitzknott

Would any of ye mind giving yer opinions on this?

The topics I know well are:

Circular Motion, The Electron, Particle Physics, Heat, Sound & light waves, mirrors & lenses. I'm alright with all of mechanics overall. I'm *okay* with pressure and density.

As for experiments, I know g by freefall, all the heat ones, the mirrors and lenses ones, the stretched string ones, and I'm gonna learn a few other mechanics ones that people have suggested.

I know no electricity, and my teacher said current and static electricity are likely for questions 8 & 9. Is it worth trying to learn them at this point? He predicted resistivity for questions 4 and 12 as well, so I might just have a look at resistivity.

How screwed am I, and where have I left myself open?

Broseph

sfitzknott wrote: »

Would any of ye mind giving yer opinions on this?

The topics I know well are:

Circular Motion, The Electron, Particle Physics, Heat, Sound & light waves, mirrors & lenses. I'm alright with all of mechanics overall. I'm *okay* with pressure and density.

As for experiments, I know g by freefall, all the heat ones, the mirrors and lenses ones, the stretched string ones, and I'm gonna learn a few other mechanics ones that people have suggested.

I know no electricity, and my teacher said current and static electricity are likely for questions 8 & 9. Is it worth trying to learn them at this point? He predicted resistivity for questions 4 and 12 as well, so I might just have a look at resistivity.

How screwed am I, and where have I left myself open?

You can get away with leaving pressure and density out as it comes up as a section B question and there will be either 1 or none of them. I would look at the resistivity experiment as it may give you an option on the day. By not having applied electricity, and electricity that rules out 2 questions which means you may have no choice on the day but you won't be caught as far as I can see you have enough to get through. That said, electricity undoubtedly opens up your options hugely.

DarraghF197 wrote: »

I did a quick calculation there that leaves a good bit of time. I think it's quite manageable to get an extra experiment, an extra Section B question and a Q12 part in the time given. We could take 16 minutes per experiment, and then 16 minutes per long question, 25 minutes 12, and 10 for the short questions.

Sorry, my phone keeps breaking down, really frustrating lol

Are you saying 4/4 experiments and 7/8 long questions? Why do the 2 extra long ones?

qweerty

Really don't think it's wise to aim to do more than the eight questions. If doing a ninth is to be worth it, you will have to first equal the marks you got in your eighth-best question before you start increasing your overall score, which could take twenty/twenty-five minutes. But if you've chosen your questions wisely at the start, why would you be able to pick up more marks in your ninth than eighth? The only potential benefit is if you're not sure at the start which of a number of questions will be your least-best. I'd said a LOAD of people do an extra question and either don't improve or improve so marginally that the time spent was worthless; spend it on improving your eight best questions instead. I would only do a ninth question if I've abandoned another question because it didn't go as well as I thougt it would.

Exceptions: I'd do all Q5's and an extra Q12 part. And if I were to do another full question, it would definitely be a Part B one: there are more marks on offer, they're quicker to do relative to the number of marks and you'll have a choice.

Broseph

qweerty wrote: »

Really don't think it's wise to aim to do more than the eight questions. If doing a ninth is to be worth it, you will have to first equal the marks you got in your eighth-best question before you start increasing your overall score, which could take twenty/twenty-five minutes. But if you've chosen your questions wisely at the start, why would you be able to pick up more marks in your ninth than eighth? The only potential benefit is if you're not sure at the start which of a number of questions will be your least-best. I'd said a LOAD of people do an extra question and either don't improve or improve so marginally that the time spent was worthless; spend it on improving your eight best questions instead. I would only do a ninth question if I've abandoned another question because it didn't go as well as I thougt it would.

Exceptions: I'd do all Q5's and an extra Q12 part. And if I were to do another full question, it would definitely be a Part B one: there are more marks on offer, they're quicker to do relative to the number of marks and you'll have a choice.

No fourth experiment question then? It seems just as easy to lose marks there

DarraghF197

Broseph wrote: »

Are you saying 4/4 experiments and 7/8 long questions? Why do the 2 extra long ones?

No, six long questions. What I have covered is:

Mechanics
L/H/S
Modern Physics
Particle Physics
Electrostatics and Capacitance.

It's likely I'll have four questions to answer on them and then I can do 12 and 5.

Above my post, yeah I understand. Sometimes it is better to just focus solely on the minimum questions and do the best possible there. It seems to happen a bit that the marking schemes can be pretty horrible and you have to mention key words/phrases to get marks, and consequently cab lose quite a bit just because of not directly adhering to the marking scheme. That's why I think it might be better to do extra, and also because I think I will have plenty of time.