0
$\begingroup$

How to calculate the energy required to rotate a planet from non-rotating state? Say the planet is Venus with equally distributed mass of $4.8676 \times 10^{24}$ kg, and desired rate of 1 rotation per 24 hours.

$\endgroup$
6
$\begingroup$

The rotational energy of a body is given by:

$$ E = \tfrac{1}{2}I\omega^2 $$

where $I$ is the moment of inertia and $\omega$ is the angular velocity. For a uniform sphere the moment of inertia is related to the mass of the sphere, $m$, and the radius of the sphere, $r$, by:

$$ I = \frac{2}{5}mr^2 $$

You already have the mass, and you can Google for the radius of Venus. That will give you everything you need to answer the question.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.