Recent content by grahammtb

Thanks very much! It was a typo, thankfully. :-p

Homework Statement A particle sits at the top of a sphere of fixed radius a. It is given a tiny nudge and begins to slide down the frictionless surface of the sphere. My attachment won't work so I'll try and explain. Theta, \theta, is the angle which the particle makes with the vertical axis...

yep! It worked! Thanks a lot guys, I'd have spent all afternoon trying to pick my way through :)

Ah I think I see...so if dV = Ady, then I can put that into my original eqn. for CoM? R = (1/M)\int\rhoydV. Then R = (Pi.\rho/M)\inty3dy...I think :redface:

Ok, since the discs are extremely thin, I'd approximate the volume of the disc to be its area. So: A(y) = Pi.(r(y))2.

Hi there, I can't get my head round how to do the math for this problem. I'm sure it's not as hard as I think... Homework Statement Show that the CoM of a uniform solid hemisphere of radius r lies at a distance (3/8)r from the centre of the flat face. You may find it convenient to regard the...

Oh, I probably made a silly mistake when I did the integral. At least it confirms my answer of 56 :smile:

Nah, you're not crazy - its all interesting stuff! One of my lecturers told me an interesting way to think of the Big Bang. It could well have come from a point in space, in fact it had to if everything was condensed to a 'point'. But at the same time, all the space everything was inside was...

thank you for your opinion. I've been working away at a few different problems and I seem to have them sorted out now :approve: I found some examples on my physics department website which helped. I did agree with you about solving the integral from 2 to \infty but I tried it and it doesn't...

Hi, I've got a solution to this problem but I don't know if it's correct. My lecturer hasn't given us any examples but I had a go and the answer seems fine. Here it is: The IMF of a cluster of stars is: dN\proptom-2.5dm There are 5 stars in the cluster with mass greater than 10 solar masses...