college physics

Estimate the rotational kinetic energy of Earth, assuming it to be a solid sphere of uniform density.

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  1. the equation used here i believe is

    K=1/2lw^2

    k=KE due to rotation
    l=moment of inertia about rotation axis
    w=angular velocity

    l=2/5mr^2

    m=mass of sphere
    r=radius of earth

    you have to look up all these numbers i believe
    i found the mass of the earth to be:
    5.97*10^24kg
    and the radius to be:
    6.37*10^6m or 6371 km
    and the angular velocity to be:
    7.27*10^-5 rad/s

    plugging that all in i believe is how you estimate the rotational KE. let me know what you get and we'll compare.

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  2. hey..i got 5.52940206x10^26

    is that what you got? what are the units?

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