Gravitational Force vs Weight

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Everyone experiences gravity acting on them at all times on earth. Without it we (and everything else on earth) would be floating around in space.



The term gravitational force describes the attractive force acting on all of the entities involved. For example, take two boxes, A and B. We know from Newton's Third Law of Motion that irrespective of their masses, the strength (or magnitude) of the gravitational pull experienced by each object will be exactly the same, although opposite in direction. Newton's Second Law of Motion tells us that if the two objects have an identical mass, they will move towards each other at the exact same acceleration.



If the masses of the two objects are different, both objects will still experience the same gravitational pull; however the lighter object will be pulled at a faster rate towards the heavier object.



The mass of the earth is MUCH greater than the mass of a person. This means that if we were floating a few hundred kilometers from the earth in space, we would be pulled towards it at a MUCH faster rate than the earth would be pulled towards us.



Weight is the name given to this phenomenon; you can think of it as the gravitational force at the surface of extraterrestrial bodies such as the earth or moon. All of us experience it, and it varies depending on the masses of the two bodies. It is measured and reported either using the unit kg⋅m/s2 or Newton (N) (after the famous physicist and mathematician Sir Isaac Newton).