# Physics Concepts for JEE 2016: Gravitational Field due to Extended Bodies

As already covered, the gravitational field

strength at a point in space is given by the force experienced by a unit mass

placed at that point, and gravitational field strength due to a point mass can

be easily calculated by the ratio of the force experienced by a test mass

placed at that point.

In case of an extended body to calculate

the gravitational field strength at any point in its surrounding, we consider

an elemental mass in the body and find the gravitational field strength at that

point due to this elemental mass, and integrate the result for the whole mass

of body. To understand this, see the video given below.

Using the above logic, gravitational field

strength due to various bodies can be calculated. There are several bodies

considered as standard bodies of which gravitational field can be calculated

using this logic, and are used in forming the basics of many fundamental

numerical problems. See the videos given below for gravitational field strength

due to some standard bodies.

Gravitational Field Strength due to a

Uniform Rod: https://youtu.be/ab61X9iQtcg

Gravitational Field Strength due to a

Uniform Ring: https://youtu.be/z42ypASf-Uk

Gravitational Field Strength due to a

Circular Arc: https://youtu.be/7TsMKbqOo4Q