Edexcel M2/M3 June 6th/10th 2013

They have appeared now. I've done the UK one (see below). I'm just starting the international one.

For the UK one, I think I agree with Idknow on everything except 7(c), where you needed to get the answers in terms of a, g and t only.

It got pretty tough towards the end, didn't it?

EDIT: Thanks for people's corrections. I've altered my answers as needed by corrections as notified by about 1 p.m., today, Wednesday the 12th.

EDIT, 31 July: I've now added versions checked against the official markschemes. The only difference in the M3R paper is correcting a slip in the arithmetic in Q2. In the M3 paper, I've reinstated the integration in the centres of mass question, as it was clearly asked for and was needed for full marks. But I've pointed out how you can keep the workload down by going to the calculator as soon as you have a numerical expression to evaluate.

Best use the "CHECKED" versions from now on.

Hello
for 7c i dont see how resolving in the horizontal direction for the x-coordinate produces utsin(alpha) shouldnt it be cos(alpha) and the vertical should be sin(alpha) in terms of components, and then simply take away the horizontal and vertical distances to obtain the coordinates? Im not sure that the mark scheme is correct on this front.

Be careful where you've put your angle alpha at B.

Once this mark scheme has been used to mark a few 1000 scripts, any errors would probably have been noticed.

Be careful where you've put your angle alpha at B.

Once this mark scheme has been used to mark a few 1000 scripts, any errors would probably have been noticed.

I thought the velocity is tangential at B, just at the instant when the string is slack, does this assumption hold when finding out components? this is how i marked in the angle alpha by using alternate angles at point B and then using SUVAT for horizontal and vertical components? it is just the components i am confused about. The initial positions bit to find the coordinates is quite comprehensive.

Hello
i have attached an image of the angle alpha i was referring to whilst attempting to obtain the SUVAT equations.
cheers

I begin to see your problem(s). The string won't go slack while the particle is in the bottom half of the circle but once it is in the top half (tie something on to the end of a piece of string and whirl it round in a vertical circle at different speeds).

Also theta is measured from the "downward vertical through O". Yours appears to be measured from OA.