Resultant Gravitational Force and Neutral Point

Resultant force at any corner of the triangle

Gravitational force is the force acting between every two bodies in the universe and it depends on the mass of the bodies and is inversely proportional to the square of the distance of the separation. The force between any two bodies is independent of the presence of the third body. If multiple bodies are there around a body, we need to find the resultant of all the existing forces using the vector laws of addition like parallelogram law.

Let us consider a scenario. Three particles at the three corners of a equilateral triangle. We would like to measure the resultant force acting on any one mass at any one corner of the triangle. For the sake of simplicity, let us assume that the three particles are identical and having the same mass. Each particle experience attractive force due to other two masses and this two forces do have an angular separation of sixty degree.

We can find the resultant of the two forces can be found using parallelogram law of vectors. In  the following video, a lesson is uploaded where, we are going to measure the resultant force.

Neutral Point
Let us consider two particles of different masses are separated over a line with a certain distance of separation. Let us consider a third mass particle in between them. This particle experience force of attraction due to both of them. These two forces are opposite in the direction on the third body. If this two forces are equal in the magnitude, these two forces cancel each other. Then the resultant force on the third body is zero and that particular point is called neutral point.
In the following video, expression for neutral point is derived as shown below.



Related Posts

Moment of Inertia in Rotational Motion Compared with Mass

Parallel and Perpendicular Axes Theorem of Moment of Inertia

Moment of inertia of a Ring and Disc

Moment of Inertia of Solid Sphere, Halo Sphere and Thin Rod

Combined motion of body on horizontal and inclined surface

Conservation of Angular Momentum and Applications

Gravitational Force of Attraction and Newton's Law