Question

Determine the escape velocity of a body from the moon assuming moon to be a uniform sphere of radius 1.74 × 10⁶m and mass 7.36 × 10²²kg. Based on the answer explain why moon has no atmosphere.

(G = 6.67 × 10^-11 Nm²kg^-2 ).

Answer 1

Escape velocity is given by,

= 2.38 × 10³ ms^-1

= 2.38 km s^-1

The escape velocity from the moon is 2.38k ms^-1 which is less than the r.m.s. value of velocity of gas molecule. Hence all gases which might have been on the surface of the moon had escaped from moon. Hence moon has no atmosphere.