A particle moves from position 1 to 2. If there is no friction, work done on the particle is Wh1-Wh2, because the change in potential energy is W(h2-h1) .
Whether the particle follows path on the left side or path on the right side, the work done is same. However, if the friction is present, the work done will be different on both cases.
Principle of total minimum Potential Energy |
Thus , the conservative force field is expressible in the form of negative gradient of potential energy. |