**Applied Maths Before/After**

Bionicle

I really rushed through q3 but does (a)30 degrees and (b) 31.72 degrees ring a bell?

NierellaA

Bionicle wrote: »

I've been doing some of the questions and can confirm that for q5(b), the answers are e=1/2, e=1/3, thickness is 3.75 cm and that the answers for q10 (a) is 1.5, (b) 60 m/s and 36m. I'll get crcking on more questions if you guys want. Any in particular?

Greatest news I've heard all day!

Bionicle

I got the same answers as the teacher that posted. I tried q6 part b and got (i) Upper: m(w^2.l+g) and lower m(w^2.l-g) (ii)sqrt(6l/g)

johnccc

Hi, for question 6 did anyone get for the period pi/sqrt5 and the position of equilibrium as .49.

for part b did you get ml(w^2) + mg and ml(w^2) - mg for the tensions

and 2(sqrt(L/g)) for the time which elapses.

So p**sed of with 2b didn`t realise how easy it was until i finished.

ahmdoda

johnccc wrote: »

Hi, for question 6 did anyone get for the period pi/sqrt5 and the position of equilibrium as .49.

for part b did you get ml(w^2) + mg and ml(w^2) - mg for the tensions

and 2(sqrt(L/g)) for the time which elapses.

So p**sed of with 2b didn`t realise how easy it was until i finished.

yes the only thing that got me was the time that elapses it seems that your answer is correct but how did u work it out?

Undeadfred

johnccc wrote: »

Hi, for question 6 did anyone get for the period pi/sqrt5 and the position of equilibrium as .49.

for part b did you get ml(w^2) + mg and ml(w^2) - mg for the tensions

and 2(sqrt(L/g)) for the time which elapses.

So p**sed of with 2b didn`t realise how easy it was until i finished.

Yeah i got that

Undeadfred

appliedmaths wrote: »

I have put up (draft) solutions to qu1,2,3,4,5,10 on CBS Kilkenny Moodle.
Hope they are correct! But pls feel free...!

I can't access that, I dont have an account. how do i get solutions?

Undeadfred

It's ok i got it.

for the last part of Q.5, i got 15/8 or 1.875 for the thickness of the paper and i strongly believe this is right. Did anyone else get this?

Did it by doing e=k(thickness of paper) where k is a constant. Found k by putting in the values they give you in the question, then put in a quarter for e to solve for the new thickness of paper

johnccc

The vertical velocity is 0 and the distance is -2l and a is g so you i just worked it out from that.

ahmdoda

johnccc wrote: »

The vertical velocity is 0 and the distance is -2l and a is g so you i just worked it out from that.

ahhhhhhhh cant believe i couldnt think of that!! i overcomplicated it by using mv^2/r equation to find a value for v and then using v=u+at with v=0 clearly didnt work

ahmdoda

Undeadfred wrote: »

It's ok i got it.

for the last part of Q.5, i got 15/8 or 1.875 for the thickness of the paper and i strongly believe this is right. Did anyone else get this?

Did it by doing e=k(thickness of paper) where k is a constant. Found k by putting in the values they give you in the question, then put in a quarter for e to solve for the new thickness of paper

yep thats why i did but it seems to be wrong was really banking in q5 to be one of my best but screwed it up

Undeadfred

ahmdoda wrote: »

yep thats why i did but it seems to be wrong was really banking in q5 to be one of my best but screwed it up

It shouldn't be though that makes perfect sense and tbh the solution on moodle doesn't seem as straightforward so it could be wrong

Bionicle

johnccc wrote: »

The vertical velocity is 0 and the distance is -2l and a is g so you i just worked it out from that.

The distance is 3l. BC is 2l and thenyou have to go half way up between A and C which is l so the total is 3l.

@Undeadfred: The solution on moodle is correct for q5. I did it another way and got the exact same answer. If you want, I'll do up a solution for it.

Bionicle

Sheet 1

Bionicle

Sheet 2

Bionicle

Sheet 3

If you think about it, if the ball rises upless in (iii) than (ii), then the paper must be thicker in (iii) than in (ii), hence why it cant be 1.8

johnccc

ahhhhhhhh noo i never thought of that!! hopefully i ll just lose two marks

xJEx

Undeadfred wrote: »

I can't access that, I dont have an account. how do i get solutions?

You can you just log in as a guest I did it

xJEx

Undeadfred wrote: »

It's ok i got it.

for the last part of Q.5, i got 15/8 or 1.875 for the thickness of the paper and i strongly believe this is right. Did anyone else get this?

Did it by doing e=k(thickness of paper) where k is a constant. Found k by putting in the values they give you in the question, then put in a quarter for e to solve for the new thickness of paper

Your answer is wrong, everyone keeps saying this. E is not proportional, the CHANGE in e is proportional

Hsiecjshjsvss

Did anyone do a graph for q 5c and 10(last part). I drew a graph and got the equation of the line and subbed in whatever. I know I got the answers right but do you think I'll get any marks for it?

Undeadfred

Bionicle wrote: »

Sheet 3

If you think about it, if the ball rises upless in (iii) than (ii), then the paper must be thicker in (iii) than in (ii), hence why it cant be 1.8

Yeah you're right...

God that's annoying. What i did seemed so logical as well. It's those little trick questions like that which made the paper that much harder than previous years. I heard that they Modified the paper to reduce the A1 rate in Applied Maths

Undeadfred

btw, did anyone get like 52 degrees for Q.7(a)?

xJEx

Undeadfred wrote: »

Yeah you're right...

God that's annoying. What i did seemed so logical as well. It's those little trick questions like that which made the paper that much harder than previous years. I heard that they Modified the paper to reduce the A1 rate in Applied Maths

Really who said that? I thought it was a lot easier than my mock anyway

Undeadfred

xJEx wrote: »

Really who said that? I thought it was a lot easier than my mock anyway

Its a rumour mixed with personal opinion. I found it quite a sneaky paper, purposely trying to catch students out. Very unconventional paper. Not what i was expecting. It caught me off guard.

Bionicle

Although it was slightly different from other years, it wasn't particularly difficult. Okay there was a few tricky parts, but there has always been tricky parts in any other year. I thought it was a standard paper and managed to maintain the same level of difficulty as in any other year. You'll be getting the same % of A's, B's, and C's this year, I assure you. The people that take up this subject to begin with are those with a mathematical aptitude so although some parts were different, they were still very manageable.

Undeadfred

Bionicle wrote: »

Although it was slightly different from other years, it wasn't particularly difficult. Okay there was a few tricky parts, but there has always been tricky parts in any other year. I thought it was a standard paper and managed to maintain the same level of difficulty as in any other year. You'll be getting the same % of A's, B's, and C's this year, I assure you. The people that take up this subject to begin with are those with a mathematical aptitude so although some parts were different, they were still very manageable.

Yeah it wasn't that bad. Just new. There has never been a question like question 5 before, and never a part C to question 10. We were all preparing ourselves for a paper that didn't come up, and for that reason it required more thinking on the spot, something that is difficult to do in an exam.

Would you mind putting up a solution to Q.7(a)? Both me and my friend got loads of disgusting trig equations for that one. I eventually got an answer to it but I'm unsure if its right

lostatsea

Undeadfred wrote: »

Yeah it wasn't that bad. Just new. There has never been a question like question 5 before, and never a part C to question 10. We were all preparing ourselves for a paper that didn't come up, and for that reason it required more thinking on the spot, something that is difficult to do in an exam.

Would you mind putting up a solution to Q.7(a)? Both me and my friend got loads of disgusting trig equations for that one. I eventually got an answer to it but I'm unsure if its right

Answer 7 (a): 62.2 degrees or inverse cos of 7 over 15.
The 15 N vector is the resultant of the other 2 forces. Use the cosine rule to find theta.

ahmdoda

lostatsea wrote: »

Answer 7 (a): 62.2 degrees or inverse cos of 7 over 15.
The 15 N vector is the resultant of the other 2 forces. Use the cosine rule to find theta.

i got 62.something but used a different approach basically resolving the forces saying left = right and up=down and then finding an expression in term of theta to work it out

Bionicle

Undeadfred wrote: »

Yeah it wasn't that bad. Just new. There has never been a question like question 5 before, and never a part C to question 10. We were all preparing ourselves for a paper that didn't come up, and for that reason it required more thinking on the spot, something that is difficult to do in an exam.

Would you mind putting up a solution to Q.7(a)? Both me and my friend got loads of disgusting trig equations for that one. I eventually got an answer to it but I'm unsure if its right

Believe me, I know about thinking on the spot. It can be an absolute biatch! :P You will learn from this for college; you should focus more on understanding the concept more so than learning the procedure. That is the difference between an A1 and the rest. I'm sure you will do fine though and will not be heavily penalised for that mistake.

Unfortunately, I never learned statics. I tried to but always ended up picking the wrong points to take moments and just gave up on it. :P I'll have a look at it and try give you an answer, however .:)

Undeadfred

Bionicle wrote: »

Believe me, I know about thinking on the spot. It can be an absolute biatch! :P You will learn from this for college; you should focus more on understanding the concept more so than learning the procedure. That is the difference between an A1 and the rest. I'm sure you will do fine though and will not be heavily penalised for that mistake.

Unfortunately, I never learned statics. I tried to but always ended up picking the wrong points to take moments and just gave up on it. :P I'll have a look at it and try give you an answer, however .:)

Sound advice, thanks

Bionicle wrote: »

i got 62.something but used a different approach basically resolving the forces saying left = right and up=down and then finding an expression in term of theta to work it out

I also did this but it lead to some very ugly and long equations that took ages to figure out. Don't have a clue how to do it the way lostatsea says