Question

If the kinetic energy of rotation of a body is doubled, then its angular momentum ____________.

Options

• becomes one fourth

• becomes half

• becomes `sqrt2` times its initial value

• becomes doubled

Answer 1

If the kinetic energy of rotation of a body is doubled, then its angular momentum becomes `sqrt2` times its initial value.

Explanation:

K.E. of rotation of a body = `1/2 I omega^2 = L^2/(2I)`

∴ L² = 2I (K.E.)

Now K.E. is doubled.

∴ L'² = 2I. (2K.E.) = 2L

or L' =`sqrt2` L.