The second condition assures those torques are also balanced. The perpendicular lever arm r ⊥ is defined to be r ⊥ = r sin θ so that τ = r ⊥ F

The perpendicular lever arm r ⊥ is the shortest distance from the pivot point to the line along which F acts. The SI unit for torque is newton-meter (N·m) .

torque — turning or twisting effectiveness of a force. perpendicular lever arm — the shortest distance from the pivot point to the line along which F lies. perpendicular lever arm r ⊥ — defined to be r ⊥ = r sin θ so that τ = r ⊥ F. dynamic equilibrium — a state of equilibrium in which the net external force and torque on a system moving with constant velocity are zero.