MCQ
With what velocity should a particle be projected so that its height becomes equal to radius of earth?
  • $\left(\frac{G M}{R}\right)^{1 / 2}$
  • B
    $\left(\frac{8 G M}{R}\right)^{1 / 2}$
  • C
    $\left(\frac{2 G M}{R}\right)^{1 / 2}$
  • D
    $\left(\frac{4 G M}{R}\right)^{1 / 2}$

Answer

Correct option: A.
$\left(\frac{G M}{R}\right)^{1 / 2}$
a
$v^{2}=\frac{2 g h}{1+\frac{h}{R}}$

given $h=R$.

$v=\sqrt{g R}=\sqrt{\frac{G M}{R}} .$

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