I understand Denverdoc, thanks for the lead... I think I've got a good answer using the conservation laws: m1v1 = m2v2, and I=mr^2
the answer is very small however, with I = 2.00x10-5kg m^2 does this sound anything like what you would expect??
A horizontal disk of diameter 12.0cm is spinning freely about a vertical axis through its centre at an angular speed of 72 revolutions per minute. A piece of putty of mass 5.0g drops on to and sticks to the disk a distance of 4.0cm from the centre. The angular speed reduces to 60 revolutions per...