MCQ
The angular velocity of rotation of star (of mass $M$ and radius $R$) at which the matter start to escape from its equator will be
  • A
    $\sqrt {\frac{{2G{M^2}}}{R}} $
  • B
    $\sqrt {\frac{{2GM}}{g}} $
  • $\sqrt {\frac{{2GM}}{{{R^3}}}} $
  • D
    $\sqrt {\frac{{2GR}}{M}} $

Answer

Correct option: C.
$\sqrt {\frac{{2GM}}{{{R^3}}}} $
c
(c) Escape velocity $v = \sqrt {\frac{{2GM}}{R}} $

If star rotates with angular velocity $\omega$ then $\omega = \frac{v}{R} = \frac{1}{R}\sqrt {\frac{{2GM}}{R}} = \sqrt {\frac{{2GM}}{{{R^3}}}} $

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