The force of gravity acting on a body having unit mass placed on or near the surface of the Earth is known as acceleration due to gravity.
Let the earth to be a sphere of radius R and uniform density ρ, then mass will be
Mass = Volume ×Density
![Acceleration Due To Gravity Of Earth](https://mrmanojpandey.com/wp-content/uploads/2023/06/Acceleration_due_to_gravity_of_earth.jpg)
If point mass m is situated on the earth surface, then r = R and the gravitational force on the earth surface on mass m is
![Acceleration Due To Gravity Of Earth](https://mrmanojpandey.com/wp-content/uploads/2023/06/Acceleration_due_to_gravity_of_earth1.jpg)
Let the mass m experiences acceleration g, called the acceleration due to gravity, then according to Newton’s second law of motion
![Acceleration Due To Gravity Of Earth](https://mrmanojpandey.com/wp-content/uploads/2023/06/Acceleration_due_to_gravity_of_earth2.jpg)
This gives the acceleration due to gravity on the surface of the earth.
Substituting the value of M = 6.4×10²⁴ kg and R = 6.4×10⁶ m, we get g = 9.8 m/s².