Question

How strong is the force of gravity on Earth?

Answer 1

Hint:Gravity is the weakest of all the four fundamental forces and the strong nuclear force is the strongest force. If we talk about astronomical Scale or on a large scale, Gravity seems to be stronger than any of the other forces. Sometimes this confuses the students about how gravity can be the weakest force.

Complete answer:
You might be thinking that gravity is the weakest force, Earth gravity is strong and Because of Gravity we are revolving around the sun which is around 147 million KM away from us.
Well let’s discuss the answer, Gravity is a long-range force, but it is not a strong force. Let’s take an example, Whole Earth’s gravity is attracting you toward the surface or center of earth but still you can easily jump on the surface. Now think of a small tiny magnet whose force is enough strong that you need to do a bit of struggle to separate two magnets. Now think of nuclear force, how a nucleus which is even smaller than an atom can exert a strong force on its nucleons that you can’t separate them. If they are of the size of earth then you can’t even assume how strong they will be. You require an energy of thousands of Mega Electron Volt (MeV) to separate a nucleon from a nucleus and you just require a little energy to throw a ball in the air against gravity.
If we talk about earth you know that acceleration due to gravity is 9.8 meter per second ($9.8m{{s}^{-1}}$) this means the force of gravity is 9.8 newton per kg (9.8 N/Kg)

Note:
Gravity is a two-body force, you need to have at least 2 bodies to calculate the force of gravity on each other. Gravity is always applied by one body to another, A massive body can not apply gravity due to his mass on itself. So, if you are experiencing a gravitational force while sitting on earth this is only because your force of gravity is interacting with the Earth’s Force of gravity. If you were massless then you won’t be feeling the force of gravity of Earth, because you will not be having a gravity of yourself to interact with gravity of Earth.