What is the Universal Law of Gravitation?
According to the universal law of gravitation, every object in the universe attracts every other object 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 us try to understand this law.
Consider two objects A and B separated by a distance ‘d’. The distance between the centres is
considered as the distance between the two objects. Let us assume that the mass of object A is
𝑚1 and that of object B is 𝑚2. As object A is bigger, let’s assume 𝑚1 > 𝑚2.
Two Objects Separated by a Distance
According to the universal law of gravitation,
𝐹𝑜𝑟𝑐𝑒 ∝ 𝑚1 × 𝑚2
And,
𝐹𝑜𝑟𝑐𝑒 ∝ 1/𝑑2
The given relationship can be represented as follows:
𝑭 ∝ (𝒎𝟏×𝒎𝟐)/𝒅𝟐
So, if the mass of any of the objects increases, the gravitational force will have more magnitude. More the distance between the two objects, the lesser the gravitational force.
The gravitational force formula can be written by introducing a proportionality constant ‘G’ as
follows:
𝑭 = 𝑮
(𝒎𝟏 × 𝒎𝟐)/𝒅𝟐
The proportionality constant G is called the universal gravitational constant.
The universally accepted gravitational constant value is as follows:
𝑮 = 𝟔. 𝟔𝟕𝟑 × 𝟏𝟎−𝟏𝟏𝑵 𝒎𝟐 𝒌𝒈−𝟐