For motion under central forces, which quantity will be conserved ?

Step-by-step solution

A central force is a force that is directed along the line joining the source of the force and the particle, and its magnitude depends only on the distance r from the source. Such a force can be expressed as F = f(r) r . Since the force is purely radial, the torque = r F = r f(r) r = 0 . Consequently, the angular momentum L is conserved. Furthermore, a central force is a conservative force because it is a function of position only and its curl is zero. For any conservative force field, the total mechanical energy E