The mass of the moon is `1//9` that of the earth. The value of the gravitational force of the earth on the moon is F newton. What is magnitude of the gravitational force of the moon on the earth.

Explanation

g on the surface of the earth is given by `g'=(GM)//(R^2)`and for the planet `g'= (GM')/R^2=G. (5M)/(R^2) therefore g'/g=5therefore g'=5g therefore` Work done in liffing the stone, through a distance of 1 m is `W= mg'h = 5xx 3xx10xx1 = 150 J`