Recent content by gupster

I'm the girl who posts on punktastic...

This is an adaptation of question 2.1. in Galactic Dynamics by Binney and Tremaine in case anyone owns it. Homework Statement Astronauts orbiting a planet find that (i) the surface of the planet is precisely spherical. (ii) the potential exterior to the planetary surface is \phi =...

I've hit a snag when trying to calcuate the moment of inertia for when his arms are by his side because I don't know the radius of his arms. I've said I_arm = I + Md^2 where I = MR^2 and d is the distance from the axis i.e. R_body+R_arm

Oops yeah that notation is the wrong way round. I can't seem to edit my original post though. So I do the moment of inertia for body+arms for each case and then assume momentum is conserved? That's the only other thing I can think of that is conserved! I'll have a go at that now then. I feel...

Practice question for a general physics exam - I'm a 4th year undergraduate but have mostly taken astrophysics courses this year so am a bit stuck going back to general physics... Homework Statement A skater spins with angular velocity \omega = 6 rad/s with his arms extended. How fast will...