How can we find the no of degrees of freedom ?? For example:- An ant is moving on a horizontal surface. The no of degrees of freedom of the ant will be ?

Hi,

A degree of freedom is an independent physical parameter (often called dimension) which helps in describing the state of the physical system. Let us now understand the concept in more detail, Suppose a particle is constrained to move in a straight line then we will say it has 1 degree of freedom.

If the particle is a molecule of gas , it will have three degrees of freedom as gas occupies the 3-D space. The degrees of freedom change when the number of particles change for eg for a mono-atomic gas, the indivisual degrees of freedom is 3 but the degree of freedom for the system as a whole will be 2*3 = 6.

In general, for N number of particles in 3-D space , degrees of freedom of the system is said to be 3N.

For the given problem, there is an ant moving on a horizontal surface. Hence there are only 2 dimensions required to describe the motion of the ant , hence the degrees of freedom for the given system is 2.

Another point to be kept in mind while calculating degrees of freedom is that if there are n number of constraints while describing the motion , then the total degrees of freedom decrease by n that is:

Degrees of freedom = 3N – n, where n is the number of constraints.