I am having some trouble with this one, so any help would be appreciated in deriving the equation. Here is the part that I need help on: Given the rotational inertia of the rod-disk system about the center of mass is 5/24ML^2, derive an expression for the angular speed of the rod-disk system immediately after the collision.

Which best represents the law of conservation of mass ?

What organization and environment is described above?

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?