he expressed the law of gravitation when an apple fell on his head
Fail.
You have given a classically silly answer.
Back to class, get the correct answer (hint, consider the inverse squared law in your answer).
Isaac newton created the universal law of gravitation.
The universal law of gravitation is given by Issac Newton.
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The distance used in Newton's law of gravitation is the distance between the centers of mass of two objects.
newton first law of motion newton second law of motion newton third law of motion newton gravitation law of motion
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Isaac Newton discovered the universal law of gravitation in 1687.
The Law of Universal Gravitation is derived from observations by Isaac Newton, called induction.
He was in an orchard examining apples falling when he formulated the Universal Law of Gravitation.
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Newton.
Sir Isaac Newton.