Question

ye gravitational wale chapter m, capital G aur small g ka kya matlab h?​

Answer 1

Explanation:

Lowercase $g$ :

Well $g$ is the acceleration due to gravity.

If a body falls from a height, you would have noticed it's speed increases every second. Every second the speed increases by same amount and we call that about $g$. If you recall from the last chapter, i.e., Motion that the how much speed changes is measured using a physical quantity acceleration, it will be easy to guess that g is also a kind of acceleration and it's value to approximated to be $9.8m/{s}^{2}$.

Uppercase $G$ :

$G$ is a constant of proportionality.

What does that mean? Let me tell you about its origins to make you understand.

In his book "Philosophiae Naturalis Principia Mathematica", Sir Isaac Newton told us that the force of gravitation is directly proportional to the masses of the two bodies on which it is acting and inversely proportional to the distance between them.

If you remember from last class direct proportions can be expressed like this :

$\frac{a}{b}=c$

where a and b are the two quantities and c is the constant you get after dividing them.

If we look at Universal Gravitation it can be written like this :

$\frac{F}{(M×m)/{r}^{2}}=G$

where F is the force of gravitation, M is the mass of first body, m is the mass of the second body, r is the distance and G is the constant.

The value of $G$ was calculated by Henry Cavendish to be about $6.67×{10}^{-11}N{m}^{2}{kg}^{-2}$.

It's discover led to the subsequent discovery of the mass of the Earth.