M3 Edexcel June 16th Revision Thread

guys! do we need to know how to prove the centre of mass of cylinders, hemispheres etc, using integration??

grade boundaries for june 09 are great. I wish they are the same for this paper :/

Did you do the paper? It was really hard! I managed a high UMS on that one, but it gave me a headache doing it!

I've got a horrible feeling a question like the following will come up, so have I done it right?



Two red lines are two different elastic springs.

Hi there, i plan to take this exam in january along with M2 i understand you need some parts of core 4 for it, what chapters in C4 will i need to learn before learning M3?

Did you do the paper? It was really hard! I managed a high UMS on that one, but it gave me a headache doing it!

I've got a horrible feeling a question like the following will come up, so have I done it right?



Two red lines are two different elastic springs.

Is it always 2 tension forces acting on a string in that position?

they are two different springs so I guess so.

Integration (no trig functions). Just basic integration that we learnt in C2, and integration of x^-1. That's all I can think of?! And just basic differentiation and the chain rule for kinematics. But honestly your M2 book will cover it all it's fine, you won't need to look over any C4.

Yep also two tensions if the particle is in the middle of a string.

Also, I've noticed the examples through the NEW M3 textbook seem to have a few mistakes in. One which is annoying me now is on page 59,chapter 3. Its part d of example 12. They get the time to be 2.47s, but that makes no sense...I keep getting exactly half that value. Could people have a look of it/try do the question and reassure me I'm not going insane trying to do this one?

Take note that it's starting point is from P. Also the particle would move through O to the left and back through O to the right again and all the way back to P. Hence why it goes slack 4 times the distance (0.8) and it experiences a whole period of SHM (1/2 period at P and the other half at A), when it first starts taut and becomes taut, twice again (There and back) after passing through O. So it goes taut 4 times, each time it covers the distance 0.4.....does this make any sense ?

And also on the next page, p60. For part b of example 13 it says the amplitude is 0.4m. Surely though it is 0.5? As the eqm position is 2m from either end, right in the middle, and the ball is pulled out to 2.5m from one end. The initial displacement if 0.5 so surely amp = 0.5. No idea how they've got 0.4m. Surely a typo. Could anyone verify this one please too? Starting to think I'm going nuts!

Thanks mate