Final answer:
Equilibrium occurs when two or more forces have equal magnitudes but opposite directions, resulting in no net force or torque. This state is crucial for static structures like buildings to withstand various external forces. It involves both the balance of forces and torques.
Step-by-step explanation:
When two or more forces act to balance each other out, the condition is called equilibrium. For a point to be in equilibrium, the first condition of equilibrium is that the sum of all external forces acting on it must be zero. This implies that the forces acting must have equal magnitudes but opposite directions, effectively cancelling each other out.
Additionally, the second condition of equilibrium requires that the sum of all external torques acting on the body is zero, which ensures that there is no rotational acceleration. Examples of static equilibrium include a building designed by engineers and architects to withstand external forces. Regardless of the force types involved, the conditions for equilibrium are consistent: both the net external force and net torque must be zero.
In the context of gravitational forces, the force of gravity balances out the other forces acting, maintaining the equilibrium state, so that the object neither falls nor rises.