How Is the Angular Momentum of Earth Calculated?

[sammythesp3rmy]

Homework Statement

Determine the angular momentum of the Earth about its rotation axis (assume the Earth is a uniform sphere).

Homework Equations

L = Iω
I = (2/5)Mr^2
ω = 2$\pi$/T

The Attempt at a Solution

I = (2/5)(6.0 X 10^24 kg)(6.4 X 10^6m)^2
ω = 1.992 X 10^-7 rad/sec

L = (2/5)(6.0 X 10^24 kg)(6.4 X 10^6m)^2 * (1.992 X 10^-7 rad/sec)
What I get from this is 1.958 X 10^31 and the answer is supposed to be 7.1 X 10^33. where did I go wrong? Thank you

 

[TSny]

How long does it take the Earth to rotate one revolution on its axis?