Conditions for Equilibrium An object in mechanical equilibrium must satisfy 1. The net external force must be Zero ∑F=0 2. The net external torque must be zero ∑T=0 The first condition is translational equilibrium and the second is rotational equilibrium If the object is in equilibrium, then the choice of axis of rotation does not influence the calculation of the net torque The location of the axis is arbitrary Physics 121: Lecture 17, Pg 3Physics 121: Lecture 17, Pg 3 Conditions for Equilibrium An object in mechanical equilibrium must satisfy: 1. The net external force must be Zero: SF = 0 2. The net external torque must be Zero: S = 0 The first condition is translational equilibrium and the second is rotational equilibrium If the object is in equilibrium, then the choice of axis of rotation does not influence the calculation of the net torque; The location of the axis is arbitrary