I know the chances of this derivation coming up are pretty remote, but does anyone know how to derive:
a = rω2?
the a here relates to the radial acceleration which in the direction of positive unit r^ is negative, i.e. towards the center rotation. a=dv/dt always - its the definition of acceleration: In this context simply state that δv=−δθvt so ar=−ωvt=−ω2r
dont confuse a with α which is the angular acceleration, i.e. we can have a net value for a but 0 for α!
Jesus sorry folks forgot I even started this thread
Aiming for a C. As someone else's said I've just lost all motivation, got my unconditional, not doing ANYTHING to do with physics or even the sciences at uni or for my career(s)... Enjoyed the course though, tons of interesting theoretical stuff that stimulates the curiosity within me delightfully Electronic circuitry/magnetic fields can go **** itself though...
With less than a day to go, how are you all feeling? What do you think'll come up?
Hope to god(oh the irony) it'll be one of those one's where mechanics just pops up in a lot of the questions mysteriously. Derivations better not though...
Hope to god(oh the irony) it'll be one of those one's where mechanics just pops up in a lot of the questions mysteriously. Derivations better not though...
Haha yeah, I'd be happy to derive one of the equations of motion - since they haven't come up in a bit. Ultimately, I'd like it to be consistent with the previous papers, because they all seem to be quite fair with the same types of questions. I'd like it to go something like this:
After that, it normally goes Q5-8/9 Electronics and the rest on waves. I'd quite like a helical path question to come up as well, since I understand those quite well. I REALLY don't want a question about force between a number of charges, because I always seem to mess those up...
There may also be a wave-particle duality question/sub-question this year too!
Haha yeah, I'd be happy to derive one of the equations of motion - since they haven't come up in a bit. Ultimately, I'd like it to be consistent with the previous papers, because they all seem to be quite fair with the same types of questions. I'd like it to go something like this:
After that, it normally goes Q5-8/9 Electronics and the rest on waves. I'd quite like a helical path question to come up as well, since I understand those quite well. I REALLY don't want a question about force between a number of charges, because I always seem to mess those up...
There may also be a wave-particle duality question/sub-question this year too!
[hastily looks ups wave-particle duality in book]
In any case here's to everyone achieving what they're aiming for!
Btw, seeing as the exam is at 1pm, what's your tactical preperation gonna be like in the morning? What you gonna have for breakfast/lunch? At what time? When you gonna set off? What time will you wake from thy slumber? What soap will you use for a shower?!?! Assuming you're having one
In any case here's to everyone achieving what they're aiming for!
Btw, seeing as the exam is at 1pm, what's your tactical preperation gonna be like in the morning? What you gonna have for breakfast/lunch? At what time? When you gonna set off? What time will you wake from thy slumber? What soap will you use for a shower?!?! Assuming you're having one
Yeah I always fret about afternoon exam starts...
I'll probably head into school at 9 for some last minute reassurance/tears. I doubt I'll have lunch if I'm honest (Exam starts before our school's canteen opens for lunch)
I have my pens and calculator neatly placed on my table, pens spaced separately (I'm a bit obsessive compulsive, in case you couldn't tell).
Without a doubt, adrenaline will start to kick in within the next few hours and I won't be able to sleep!
I prefer exams in the afternoon, means I'll be fully awake and won't end up trying to fill out the front of the exam booklet with a non-switched-on pen...
So how did you guys find it? I found the paper quite unusual, not the same format/type of questions as previous years... I will try and type up my answers when i get home.
This was posted from The Student Room's iPhone/iPad App
I guess I found it meh? I mean it was expecting it to be really hard and I don't think it was as hard as I'd expect it to be. Think it will be some sort of miracle if I get an A though. Ah well off to university regardless!
I'm really scared I'm not getting an A after that... I messed up so many questions and I guessed the answers to some! How many marks do you think I could lose to still get an A?
So how did you guys find it? I found the paper quite unusual, not the same format/type of questions as previous years... I will try and type up my answers when i get home.
This was posted from The Student Room's iPhone/iPad App
Thought it was on the whole OK. Unit 1 questions were trickier than usual, but unit three was piss easy. Kind of a nice change in my book! :L
So how did you guys find it? I found the paper quite unusual, not the same format/type of questions as previous years... I will try and type up my answers when i get home.
Agreed, the questions did seem a bit different. Almost missed out a 3 mark question by accident, caught it in my last 10 minutes of checking over answers!
I'm really scared I'm not getting an A after that... I messed up so many questions and I guessed the answers to some! How many marks do you think I could lose to still get an A?
Depends how you did on your investigation. If you got 50% on your investigation you need around 75% in the exam to get an A.
60% on your investigation -> 72.5% on the exam 70% on your investigation -> 70% on the exam 75% on your investigation -> 68.75% on the exam 80% on your investigation -> 67.5% on the exam 90% on your investigation -> 65% on the exam 100% on your investigation -> 62.5% on the exam