Final answer:
To keep a structure in static equilibrium and ensure it remains static, the net external forces and torques acting on it must be zero, indicating that all applied forces and torques are balanced.
Step-by-step explanation:
Forces Required for a Structure to Remain Static
For a structure to remain static, it must be in a state of equilibrium where the net external force is zero and the net torque is also zero. This applies both in two-dimensional and three-dimensional scenarios. Essentially, this means that all the forces acting on the structure, whether they are contact forces such as tension, compression, and friction, or field forces like gravity, must be balanced. Additionally, the sum of torques produced by these forces around any point in the system must cancel out, ensuring that there is no rotational motion.
Engineers and architects apply this understanding in designing structures that can withstand various external forces like wind and earthquakes. They use principles of statics to ensure that the forces and torques acting on a structure do not cause it to move or rotate. This principle is evident in the design of static objects from everyday furniture to large bridges and buildings.