Gravity is a force of attraction that exists between any two masses, any two bodies, any two particles. Gravity is not just the attraction between objects and the Earth. It is an attraction that exists between all objects, everywhere in the universe. Sir Isaac Newton (1642 -- 1727) discovered that a force is required to change the speed or direction of movement of an object. He also realized that the force called " gravity " must make an apple fall from a tree, or humans and animals live on ... g = Gm/r 2 Where, g = Gravitational field G = Universal gravitational constant r = Distance This means that gravity is greater where a body is more massive and has a smaller radius. This is why even though mars is 1/10th of its mass that of the earth, the gravitational pull around mars is greater than 1/10th that of earth. Question: Calculate the gravitational field (gravitational acceleration) of an object having mass 5 times that of the earth. (g of earth = 9.8 m/s2, radius of earth = 6.3 ...
