I am disgusted today

I just don't like it when people come on here and say 'please tell me the answer to this question'. It is true this individual may well be genuine given the insight he has subsequently showed in to the subject matter. But i don't think that it hurts to question their credentials, when they come on here (tsr) doing this. he wouldn't be the first!!

I tried ....?!

I made.
I solved in retrospect that is why I put some numbers after as my solution was all in variables

Ah, I see. Is r between 1 and 3, by any chance?

it is...

Great. A very nice question btw, I'll post a solution afterwards but I'm guessing you're going to do a much neater one later anyway. I made use of the fact that $\frac{d^2r}{dt^2} = \frac{d}{dr}(\frac{1}{2}(\frac{dr}{dt})^2)$ which is a neat result that I've only ever seen once before, in a SHM problem.

I am sure we are all looking forward to seeing a really perceptive mathematical contribution from john 2054 sometime soon.

i know the chaos theory based on random fractals, the basics anyway. failing that and i'm going to have to pass up your offer sorry!

I am sure we are all looking forward to seeing a really perceptive mathematical contribution from john 2054 sometime soon.

EXCELLENT!!
I will post my method now too for completeness

Oh, I didn't see that TeeEm. Nice solution.

or the coursework.

the fact is that this kid is clearly out of his depth, and essentially with no insight in to the subject matter, is asking us to answer the question for him.

this is cheating

If i actually remembered any maths, which i don't, would be a start?!