QUESTION ONE Newton derived F=GMm/R^2 by puting one kg of sphere on the surface of earth. Now consider if the same sphere is bigger and bigger till it reach the size of earth. OR simply put imaginary earth on earth Now apply F= GMm/R2 where g = GM/d2. M= m= mass of earth = mass of imaginary earth, centre to centre distance between two masses = diameter of earth. According to universal law of gravitation; there is force of F=GM^2/d^2 between aforementioned masses. As gravities of both earths cancel out and both masses exert a force which is equal but opposit in direction on each other therefore it is wrong to say that there is force of F=GM^2/d^2 between aforementioned masses. This means that weight of mass of 1 kg of sphere is start decreasing by increasing its size on the surface of ground. ________________________________- Suppose there are two sphere of masses m1 = m2 = 1 kg, diameter of m1 = m2 = 0.5 m. Both masses are in space and the centre to center distance between them is 1 metre = r , then F= Gm1m2/r2 = G = 6.67*10-11 Newton. But technically, both masses exert a force which is equal but opposit in direction on each other (gravaties of both masses g= Gm2/r2= Gm1/r2) and hence cancel out. if not, how come F= Gm1m2/r2 = G = 6.67*10-11 Newton exist and how both are gravitating and falling masses at the same time. QUESTION TWO Let “P” is a point or an origin of two circles of radius r1=1 meter and r2= 2 meter. Consider these two circle are spheres (empty from inside) or two bangles in space. OR a spherical boiled egg with removed shell such that the center of the sperical white and yolk coinicide each other at one point say “P”. Now apply Newton’s law of gravitation i.e. F=GMm/R2 to aforementioned two masses and neglect all other local attractions. As center to center distance b/t masses is zero, therefore F= infinity but in reality it's not. Now how much force is required to separate aforementioned masses, infinity or less? If less then what about the Newton’s law?