Final answer:
Unbalanced systems are indicated by unequal forces, unbalanced torques, a non-zero net force, and a non-zero net torque on the system, all of which prevent equilibrium.
Step-by-step explanation:
Evidences of unbalanced systems involve a few key indicators. First, unequal forces acting on the system can prevent it from being in equilibrium. Second, unbalanced torques contribute to a system not being at rest or moving with a constant velocity. Thirdly, a non-zero net force indicates that there will be acceleration according to Newton's second law of motion, and thus, the system is unbalanced. Lastly, a non-zero net torque on the system can cause it to start rotating or to rotate with an increasing angular velocity, which is another sign of an unbalanced system. To determine equilibrium, one needs to apply both conditions that the net external force must be zero (net F = 0) and the net external torque must also be zero (net τ = 0). This is true regardless of whether the forces in question are gravitational or of another type.