Question

Q. What is universal law of gravitation? Explain it.

Answer 1

The universal law of gravitation was given by Newton. It is also known as Newton's law of gravitation.

According to Newton's law of gravitation:

Every body in the universe attracts every other body with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

Let two bodies A and B of masses m1 and m2 are lying at a distance r from each other & the force of attraction between these two bodies be F.

1. The force between two bodies directly proportional to the product of their masses.

F∝m1 × m2................(1)

2. The force between two bodies is inversely proportional to the square of the distance between them.

F∝1/r²..........................(2)

Combining eq 1 &2

F∝m1×m2/r²

F(gravitational force)= G ×(m1×m2/r²)

Here G is a constant known as universal gravitational constant.

The value of universal gravitational constant G is 6.67× 10-¹¹ Nm²/kg²

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