Two spheres of masses m and M are situated in air and the gravitational force between them is F. the space around the masses is now filled with a liquid of specific gravity 3. The gravitational force will now be

Options

A. 3F
B. F
C. F/3
D. F/9

Answer

B

Explanation

Gravitational force does not depend on medium. In this case time of flight of a ball `ge` 2 x 2 = 4 sec.
`because` Time of flight =`"2u"/g ge 4`

`rArr u ge rArr u ge `19.6 m/s (`because =9.8 m//s^2`)