Question

NCERT CLASS IX - Science Textbook
Chapter 10 - Gravitation

Write the formula to find the magnitude of the gravitational force between the earth and an object on the surface of the earth.

Answer 1

F=G * M1 * M2/r2 

 where ,
    f = force of attraction
   M1 & M2 are the masses 
  G = gravitational constant 
  r = distance or radius 

Answer 2

         F = G M  m  / R²

  Force F
   G = universal gravitational constant
   M = mass of Earth
   m = mass of an object on the surface of Earth
   R = radius of Earth
 
   g = acceleration due to gravity  = G M / R²

then  F = m g