Qn on Rotational Kinetic Energy

AI Thread Summary
The discussion focuses on calculating the moment of inertia of a neutron star based on its rotational kinetic energy and energy release rate. The user successfully derived the equation relating power to the moment of inertia but encountered a discrepancy between their calculated value (1.1 x 10^38) and the provided answer (1.1 x 10^30). The user expresses confidence in their solution process, indicating a potential error in the provided answer rather than their own calculations. The conversation highlights the complexities involved in astrophysical calculations and the importance of verifying results. The thread underscores the need for careful attention to detail when working with such equations.
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Homework Statement


Crab Nebula releases energy at a rate of 5x1031 W, obtaining its energy from the rotational kinetic energy K of a neutron star at its centre.
Period of neutron star's rotation = 0.0331s. T increases by 4.22 x 10-13s per second.

What is the moment of inertia of the neutron star?

Homework Equations


dK/dt = -(4\pi2I/T3) (dT/dt)
This was the first part of the question which I managed to prove already.
*Note: the pi is not supposed to be in superscript.

The Attempt at a Solution


I equated the power of the star to the above differential equation. Solving for I should be quite easy, but somehow my answer (1.1x 1038) is different from the answer provided (1.1 x 1030).
 
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Your result looks correct.

ehild
 

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