[doodinthemood]

Had a look but couldn't find any thread on this. Is anyone else doing it? I heard the January paper was hard so the June one will be too?

[Beth1234]

(Original post by doodinthemood)
Had a look but couldn't find any thread on this. Is anyone else doing it? I heard the January paper was hard so the June one will be too?

Resitting this one from January.

How's revision going?

[desijut]

(Original post by Beth1234)
Resitting this one from January.

How's revision going?

i remembered your name from the cambridge maths applicants (there werent many lol). So i checked to see how you did and it turns out our firm and insurance are the same lol

[Beth1234]

(Original post by desijut)
i remembered your name from the cambridge maths applicants (there werent many lol). So i checked to see how you did and it turns out our firm and insurance are the same lol

Lovely!

Are you taking this exam?

[desijut]

(Original post by Beth1234)
Lovely!

Are you taking this exam?

No, i saw it come up on latest discussion so i thought i'd take a look. I did M3 in Jan

[doodinthemood]

(Original post by Beth1234)
Resitting this one from January.

How's revision going?

Going ok The only thing I don't like is circular motion in vertical plane. Having to work out what should be sin or cos from scratch in the past papers.

Is it true that January was really tough?

[Beth1234]

(Original post by doodinthemood)
Going ok The only thing I don't like is circular motion in vertical plane. Having to work out what should be sin or cos from scratch in the past papers.

Is it true that January was really tough?

January's paper was, in all fairness, not too bad. I seem to remember one of the questions being somewhat unusual (and therefore, slightly tough) but otherwise, I don't remember it as being distinctly difficult...

[joshgoldman]

(Original post by Beth1234)
January's paper was, in all fairness, not too bad. I seem to remember one of the questions being somewhat unusual (and therefore, slightly tough) but otherwise, I don't remember it as being distinctly difficult...

I'm taking it, with M2 the day after! I've actually got to a point where I'm better at M3 than M2... The only thing that I occasionally find tricky is the SHM questions... hopefully it'll be a nice paper!

[koolkelv]

Anyone got revision notes on this? I'm dead because I've relied on revision guides for the previous maths exams

[conorcd]

my brother is sitting this and he couldn't find much until he paid to join LiveMaths but that wouldn't be worth it for you now. He did listen to the podcast /revision lecture at
http://www.furthermaths.org.uk/onlinerevision.php
good luck

[doodinthemood]

OH MY GOD

I found that paper brutal. Don't think I've done very well at all.

[joshgoldman]

(Original post by koolkelv)
Anyone got revision notes on this? I'm dead because I've relied on revision guides for the previous maths exams

(Original post by Beth1234)
January's paper was, in all fairness, not too bad. I seem to remember one of the questions being somewhat unusual (and therefore, slightly tough) but otherwise, I don't remember it as being distinctly difficult...

(Original post by doodinthemood)
Going ok The only thing I don't like is circular motion in vertical plane. Having to work out what should be sin or cos from scratch in the past papers.

Is it true that January was really tough?

(Original post by desijut)
No, i saw it come up on latest discussion so i thought i'd take a look. I did M3 in Jan

How did you all find it? I completely guessed the last part to the last question, apart from that I thought it wasn't too bad. Quite unusual though!

[Orrin]

Thought I did well on most, messed up Q3 ii which looking back I know exactly how to do :/ think i worked out chi wrong. Other than that and the very last question I thought it wasn't too bad, did anyone manage to do the very last question? I was clueless, just hoping i've scraped a mark with all my drawings!

[4ever_drifting]

Think I did ok, though I wasted a lot of time on the last part of the last question... on which I didn't get anywhere. Would be interested to see a solution if anyone managed it! I feel like typing random numbers that I got... but worried it will only make me feel worse if I've got tem wrong :L 3pi/5 anyone?

[doodinthemood]

Questions!
1) A light elastic string length 3b and modulus of elasticity lamda is attached to point A, distance 4b above point C, and also attached to block of mass m, distance 3b horizontally from point C.
i - show acceleration is 2lamda/5m (easy, just do t=kx)
ii - show speed upon block reaching c is given by v²=lamdab/m (harder, do conservation of energy)
iii - show that v²=lamdab/m is dimensionally consistent (I worked out the dimension of lamda by dimensional consistency, but didn't give that away )
iv - time taken for block to move = km^alphab^betalamda^delta Use dimensional analysis to find alpha beta and delta (easy)
v - when l₀=1.2 and lamda=125 and m=8, t=0.718. What is t when l₀=9 and lamda=20 and m=75 (easy, use first info to work out k then use this k to work out t in second info)

2a) i - Car of mass 800 moves in a bank of angle 18degrees in a constant speed circle radius 45m. Given that the frictional force is zero, find the speed of the car (use R big enough to counter mg, then work out horizontal component then f=mv²r to get v. I got about 11 I think)
ii - given instead that the speed is 15, find the frictional force and normal reaction (quite tricky. You have to make sure up force = down force, and radial force = mv²r. I think I got both values in the thousands, and rounded to 3 sig figs)

2b) One end of a light inextensible string is attached to point O and other end to particle of mass m. P starts vertically below O and is given horizontal velocity 7 before moving in a vertical circle centre O. The string becomes slack at v=2.8, find the length of the string. (another tricky question. You have to find both the energy conservation and the inwards force to make it work. Can't remember what I got)

3) i - A particle Q is performing SHM in vertical line. It's height x above a fixed level at time t is given by x = c + Acos(wt - thingy). Show that a=-w²(x-c). (This one was ok, I differentiated the equation twice, at which point I had no c terms, then did +w²c-w²c and fiddled it to look like how the proof wanted)
ii - See graph of displacement against time. Find c, A, w and thingy. (easy. Just plug in maximum and minimum and then work out the others)
iii - Find maximum speed of Q (V²=w²a². I think I got 5pi/3 for this, or something similar)
iv - Find the height and velocity of Q when t=0 (Height was just under halfway. 8point something I think. Again this was pretty straightforward)
v - Find distance travelled by Q between t=0 and t=14 (This was ok, and I think the question was set up for this point. I think I got precisely 33m)

4a) A uniform lamina occupies region bound by x axis, y axis and y=3-root(x). Find the coordinates of the centre of mass (Turn the handle, 9 marks. I got something like 2.7, 0.7)
4b) i - A region bound by x=2 and y²=25-x² is rotated about the x axis to form uniform solid of revolution S. Find the x coordinate of the centre of mass (more turning the handle. I got 3.0625 I think)
ii - the solid is balanced on its curved side on a slope of angle 25 from the horizontal. Find the angle the flat face of the solid makes with the horizontal. (ARRRGGHHHHH! No clue how to do this. Ruthless question. I worked out the angle the CoM makes with the corner of the solid, got that to be about 18 degrees I think. I then took a bit of a stab and fiddled the figures until getting just over 50 degrees, which seemed right, so went with that)

[joshgoldman]

(Original post by 4ever_drifting)
Think I did ok, though I wasted a lot of time on the last part of the last question... on which I didn't get anywhere. Would be interested to see a solution if anyone managed it! I feel like typing random numbers that I got... but worried it will only make me feel worse if I've got tem wrong :L 3pi/5 anyone?

Yup was 3pi/5 - drew it on my graphical to make sure!


This was posted from The Student Room's iPhone/iPad App

[joshgoldman]

(Original post by doodinthemood)
Questions!
1) A light elastic string length 3b and modulus of elasticity lamda is attached to point A, distance 4b above point C, and also attached to block of mass m, distance 3b horizontally from point C.
i - show acceleration is 2lamda/5m (easy, just do t=kx)
ii - show speed upon block reaching c is given by v²=lamdab/m (harder, do conservation of energy)
iii - show that v²=lamdab/m is dimensionally consistent (I worked out the dimension of lamda by dimensional consistency, but didn't give that away )
iv - time taken for block to move = km^alphab^betalamda^delta Use dimensional analysis to find alpha beta and delta (easy)
v - when l₀=1.2 and lamda=125 and m=8, t=0.718. What is t when l₀=9 and lamda=20 and m=75 (easy, use first info to work out k then use this k to work out t in second info)

2a) i - Car of mass 800 moves in a bank of angle 18degrees in a constant speed circle radius 45m. Given that the frictional force is zero, find the speed of the car (use R big enough to counter mg, then work out horizontal component then f=mv²r to get v. I got about 11 I think)
ii - given instead that the speed is 15, find the frictional force and normal reaction (quite tricky. You have to make sure up force = down force, and radial force = mv²r. I think I got both values in the thousands, and rounded to 3 sig figs)

2b) One end of a light inextensible string is attached to point O and other end to particle of mass m. P starts vertically below O and is given horizontal velocity 7 before moving in a vertical circle centre O. The string becomes slack at v=2.8, find the length of the string. (another tricky question. You have to find both the energy conservation and the inwards force to make it work. Can't remember what I got)

3) i - A particle Q is performing SHM in vertical line. It's height x above a fixed level at time t is given by x = c + Acos(wt - thingy). Show that a=-w²(x-c). (This one was ok, I differentiated the equation twice, at which point I had no c terms, then did +w²c-w²c and fiddled it to look like how the proof wanted)
ii - See graph of displacement against time. Find c, A, w and thingy. (easy. Just plug in maximum and minimum and then work out the others)
iii - Find maximum speed of Q (V²=w²a². I think I got 5pi/3 for this, or something similar)
iv - Find the height and velocity of Q when t=0 (Height was just under halfway. 8point something I think. Again this was pretty straightforward)
v - Find distance travelled by Q between t=0 and t=14 (This was ok, and I think the question was set up for this point. I think I got precisely 33m)

4a) A uniform lamina occupies region bound by x axis, y axis and y=3-root(x). Find the coordinates of the centre of mass (Turn the handle, 9 marks. I got something like 2.7, 0.7)
4b) i - A region bound by x=2 and y²=25-x² is rotated about the x axis to form uniform solid of revolution S. Find the x coordinate of the centre of mass (more turning the handle. I got 3.0625 I think)
ii - the solid is balanced on its curved side on a slope of angle 25 from the horizontal. Find the angle the flat face of the solid makes with the horizontal. (ARRRGGHHHHH! No clue how to do this. Ruthless question. I worked out the angle the CoM makes with the corner of the solid, got that to be about 18 degrees I think. I then took a bit of a stab and fiddled the figures until getting just over 50 degrees, which seemed right, so went with that)

I agree with you for all of it - apart from at the start, we had the modulus of elasticity rather than stiffness.
For the end, my guess was that the line that A and the c.o.m makes is parallel to XY so worked out the angle that AB makes with A and the c.o.m, then added the 25 to make 38.05 degrees (I think), was a complete guess though


This was posted from The Student Room's iPhone/iPad App

[Reminisce]

(Original post by joshgoldman)
I agree with you for all of it - apart from at the start, we had the modulus of elasticity rather than stiffness.
For the end, my guess was that the line that A and the c.o.m makes is parallel to XY so worked out the angle that AB makes with A and the c.o.m, then added the 25 to make 38.05 degrees (I think), was a complete guess though


This was posted from The Student Room's iPhone/iPad App

I am relatively confident that it is 38.05

[doodinthemood]

(Original post by joshgoldman)
I agree with you for all of it - apart from at the start, we had the modulus of elasticity rather than stiffness.
For the end, my guess was that the line that A and the c.o.m makes is parallel to XY so worked out the angle that AB makes with A and the c.o.m, then added the 25 to make 38.05 degrees (I think), was a complete guess though


This was posted from The Student Room's iPhone/iPad App

I also found out the angle AB makes with A and the Com and got 13.05374
I then said "if the c.o.m was on the curved service, this angle would be 45, and the answer for theta would be 25, as it would be perfectly parallel."
So had 45 maps to 25
13.05374 maps to the answer
Then guessed the function for this system I've just made up as being "70 minus the number" so did 70-13.05374 and got 56.95 as the answer, which seemed like it looked correct on the diagram so I put that.

Stab in the dark I know

[doodinthemood]

(Original post by Reminisce)
I am relatively confident that it is 38.05

Darn. Did you do the same method he did?