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...