Applied Maths - hardest parts??

turgon

Im trying to revise the applied maths, but I dont want to just to practice papers in case they throw a really wierd one. So my question is: what is the hardest thing(s) that can be asked for each question. Ill start

Q5 - Moving wedges
Q8 - Torque
Q10 - Vertical motion maybe, especially questions regarding POWER

Cokehead Mother

Click!

You should find that link pretty interesting. The website was created by the guy who wrote the brown Applied Maths book. He gives every question from 1983 - 2006 a difficulty rating out of 5 so you can quickly find and practise some of the more difficult questions that have come up.

Q4 - If you have the brown book, the very last question in that chapter is about as hard as they come... except maybe a pulley, two particles a wedge. Just do one of those questions. You'll be grand.

Q8 - The questions don't really tend to be so bad. The main thing with this question is that it's very different from the rest of the course so understanding is super, super vital. If you actually know wtf is going on in that chapter, you should be good for most questions. And make sure you're at least somewhat familiar with circular motion! Also, it's something real small but remember the radius of gyration formula... haven't seen that up in a while I don't think?

Q10 - Power isn't hard really. If you don't recall that P = Tv, then you're at nothing with one of these questions, but otherwise it's just the same thing you do in the power questions involving linear motion. Same for the vertical motion. If the particle is moving up then ma = -resistance - mg, if the particle is moving down then ma = mg - resistance.

raah!

Q-5 (moving wedges is 4)
finding ranges of u when you have to use 0<e<1. Hardest I've ever come across in them
Q-9 It varies between certain compound body questions (there has been one really hard one), and floating object ones
But while we are on question 4, and while we're all gabbin about apt maths. I've noticed somethign which is worry me quite a bit. I was revising Q4 there, and was doing relative acceleration with pullies and the like.

Now, for the blocks which are moving twice (I.e the ones attached to the moving pully). Is there any rules for whether you say (f-a) or (a-f).(f is acceleration of single blocks relative to thier pully, which is moving with acceleration a) In brownser it has (f-a) and this makes most sense to me, as you take the direction that the block is moving as positive. But in question 4 b in 2002 it has (a-f). In the marking scheme that is.

At first I thought it might have somethign to do with a greater overall force causing a or something. but in this 2002 the force difference seemed the same (the difference in weights between the two particles on the pully)

Peleus

Cokehead Mother wrote: »

Click!

You should find that link pretty interesting. The website was created by the guy who wrote the brown Applied Maths book. He gives every question from 1983 - 2006 a difficulty rating out of 5 so you can quickly find and practise some of the more difficult questions that have come up.

Oliver Murphy, he wrote the brown book and he's my applied maths teacher. he gave us that summary of paper paper questions. soo handy when doing the past papers! what a legend

Decerto

Friction on wedges between particle and the wedge is tricky aswell coz friction acts restricting the particle moving down the wedge but also acts against wedge moving up the particle and even the normal resultant force from the wedge to the particle is strange coz it aint just the resolved weight of the particle because the particle is moving, at least thats what i understand of it

Decerto

raah! wrote: »

Q-5 (moving wedges is 4)
finding ranges of u when you have to use 0<e<1. Hardest I've ever come across in them
Q-9 It varies between certain compound body questions (there has been one really hard one), and floating object ones
But while we are on question 4, and while we're all gabbin about apt maths. I've noticed somethign which is worry me quite a bit. I was revising Q4 there, and was doing relative acceleration with pullies and the like.

Now, for the blocks which are moving twice (I.e the ones attached to the moving pully). Is there any rules for whether you say (f-a) or (a-f).(f is acceleration of single blocks relative to thier pully, which is moving with acceleration a) In brownser it has (f-a) and this makes most sense to me, as you take the direction that the block is moving as positive. But in question 4 b in 2002 it has (a-f). In the marking scheme that is.

At first I thought it might have somethign to do with a greater overall force causing a or something. but in this 2002 the force difference seemed the same (the difference in weights between the two particles on the pully)

I find the best way to do it is to regard the particles individual acceleration (b or f) as its main one and the external one of the system (a) as relative to it, so for your equations your positive forces are the ones which go with the individual acceleration, so if its a particle going down with (b) seperate from the main system and (a) externally you treat b as the main acceleration so you get Mg-T=m(b-a), its preferance though you can treat (a) as the main accel. but your forces go according to that one and you add or subtract the other one from it

turgon

Cokehead Mother, I never did physics so topics like Power are new to me, Ive it all under wraps now though.

I did classes outside of school, and the teacher gave us handouts. In them she has done out the solutions for all the questions to about 90. So I think ill be fine. Practice now though!!!

~Candy~

hey guys...errr, i dun get this fantastic subject at all..O_o >.< i mean higher maths is away easier ..:rolleyes:wot am i gonna do next year ...

i got the applied maths paper like 2months ago, i had a look of the paper only just today..and no answers in the back????or was it just that folens paper dun do answers?

sorry i am off topic..- -

tricky D

Peleus wrote: »

Oliver Murphy, he wrote the brown book and he's my applied maths teacher. what a legend

+1
Got an A because of him many many years ago despite one or two classes turning into a chat about ancient greek stuff

raah!

Decerto wrote: »

I find the best way to do it is to regard the particles individual acceleration (b or f) as its main one and the external one of the system (a) as relative to it, so for your equations your positive forces are the ones which go with the individual acceleration, so if its a particle going down with (b) seperate from the main system and (a) externally you treat b as the main acceleration so you get Mg-T=m(b-a), its preferance though you can treat (a) as the main accel. but your forces go according to that one and you add or subtract the other one from it

Ah good stuff, that is what I had been doing up till now, but that 2002 one threw me off a bit.

Edit: Actually, the 2002 one must jsut be wrong then, it has taken the direction of the f acceleration as positive, but then still said (a-f).

Yeah the folens papers are just terrible in everyway. You can't even read half of the questions. Send oliver murphy a tenner and he gives you a nice book of papers that has answers on the back and everything. Plus there are about ten more papers in that than in the folens paper

~Candy~

raah! wrote: »

Yeah the folens papers are just terrible in everyway. You can't even read half of the questions. Send oliver murphy a tenner and he gives you a nice book of papers that has answers on the back and everything. Plus there are about ten more papers in that than in the folens paper

thanks mate ^-^

eoin2nc

Party Thursday Night FREE BEER!!!! Oh wait, wrong thread, sorry guys:D




Couldnt resist, sorry!

Cokehead Mother

~Candy~ wrote: »

hey guys...errr, i dun get this fantastic subject at all..O_o >.< i mean higher maths is away easier ..:rolleyes:wot am i gonna do next year ...You're just adjusting to a different way of thinking is all.

Don't worry about it. I thought myself Applied Maths and didn't really bother much with in 5th year, so this time last years the papers were just BS to me. I'm now on target for an A1. I was completely convinced it was a great deal harder than Maths but it isn't really. If you keep going at the questions things will eventually start clicking. You're just adjusting to a different way of thinking is all.

~Candy~

Cokehead Mother wrote: »

Don't worry about it. I thought myself Applied Maths and didn't really bother much with in 5th year, so this time last years the papers were just BS to me. I'm now on target for an A1. I was completely convinced it was a great deal harder than Maths but it isn't really. If you keep going at the questions things will eventually start clicking. You're just adjusting to a different way of thinking is all.

thx well hopefully i will get the hang it it..i don't do physics..><
,:oumm i dunno how to start study for it ..i mean the maths part makes sense , it just i dun understand the concept of things @times...