Question

NCERT CLASS IX - Science Textbook
Chapter 10 - Gravitation

Why is the weight of an object on the moon thits weight on the earth?

Answer 1

Weight of an object on a planet is the gravitational attraction force on the mass m of the object exerted by the mass M of the planet.  Let the distance between the object and the planet be = R, which is the radius of the planet.

  Newtons' law of gravitation = F = G M m / R²

       Weight = mg =  F = G m * M/R²
      
   It so happens that  Mass/Radius²  on Earth is around 6 times to that on the Moon.    Hence,  weight of an object  is 1/6th of the weight on Earth.

   Simply depends on the mass of the planet and its radius.