Gravitational Field Intensity

The force that a unit mass experiences at any level in the gravitational field tells us about the gravitational field intensity or strength of a matter. So, suppose you want to transfer a unit test mass from infinity to a gravitational field. The gravitational force applied on that unit test mass due to a larger mass for which the gravitational field is generated is called gravitational field intensity.

The mathematical equation for gravitational field intensity

A gravitational field will interact between the source mass and the test mass in a non-contact force. If the force is acting upon the body of mass m at a point in the gravitational field, say F. The intensity of the gravitational field will be defined as: 

g or E = F/m …(1)

i.e., g = F/m 

Here, g is for gravitational field strength

F is for the gravitational force

M is the mass of the object

This gravitational field intensity is a vector quantity, and it has a behaviour of magnitude and direction. Suppose more than one field intensity is acting simultaneously, at any given point. In that case, the resultant field intensity will be calculated by adding all intensities together. The strength of the field will show the field’s direction. Sometimes, instead of gravitational field intensity, you can also write a gravitational field—the S.I. unit of gravitational field intensity is N kg-1.

Let’s understand the Gravitational field intensity more clearly. Allow a body of mass m to be placed at point P. That will help you find the direction of gravitational intensity. Let’s also say that a body of unit mass is present at point A when finding the gravitational field intensity of that body. The unit mass at point A will now undergo an attractive force in extension to P.A. Due to this, the intensity at point A will become parallel to A.P. Furthermore, the intensity at point B will be in the same direction as B.P. Because of this, field intensity in vector form can be written as 

Eg, = F/M 

If that is the case, F = Eg x m

You will have to understand what the intensity means if there is 4 Nkg-1 at a point in the gravitational field. As a result, we can say that if one kg mass is placed at any point in the gravitational field, it will have a force of 4 N. If 4 kg mass is put onto that field, it will show a force of 16 N.

Gravity is the best example of gravitational field intensity. You already know that gravity causes a downward acceleration of around 9.8 m/s² in any room. So, the magnitude of the Earth’s gravitational field is 9.8 m/s² down in all sections of the room. 

What is the Gravitational field intensity formula? It can be written as: 

g = F/m

Gravitational mass

Gravitational field intensity can only be defined with the help of mass. The gravitational force states that each pair of objects has its gravitational force, which is provided by gravity in an equation:  

F = G x m1 m2 / r²

Here, G is the universal gravitational constant

m1 and m2 are masses of two objects

r is the distance between them. 

These two masses turn out to be the same in terms of mass. If these two masses are equal, we can also conclude that objects on Earth fall at the same rate. The only difference is the calculation of inertial and gravitational mass. 

Gravitational Field Intensity examples

There have been massive technological changes in the last few years, and everything has reached beyond the planet. You can also see the implementation of various space models to help get a better picture. We can observe the incredible progress that has been made in upgrading the gravitational models of the Earth and terrestrial planets during the last few decades. Satellite tracking, surface gravity, and satellite altimeter measurements are a few examples of how determining the gravitational field intensity are helpful. 

Conclusion

This article explains about the gravitational field intensity. The force that a unit mass experiences at any level in the gravitational field tells us about the gravitational field intensity. The S.I. unit of gravitational field intensity is N kg-1. The gravitational field intensity is a scalar quantity.