Compute the angular momentum of the earth arising from the following motions.

Question

(a) Earth's orbital motion around the sun.

(b) Earth's rotation on its axis.

Can someone please help me with this question? Thanks

Answer 1

(a) (earth's velocity in orbit)x(distance from sun)

(b) This requires the moment of inertia about its axis, I. Assume mass is uniformly distributed and use
I = (2/5)M*R^2
which applied to solid spheres.

The moment of inertia of rotation is
I*w
where w is the angular velocity of rotation. You can get that from the 24 hour period of a day.