Inertia is the resistance an object has to change in its state of motion. In the case of a beam hinged to a wall, inertia will cause the beam to resist any changes in its rotational motion.
Torque is the measure of the force that causes an object to rotate around an axis. In the case of a beam hinged to a wall, the torque will determine how much force is needed to rotate the beam around the hinge.
The longer the beam, the greater its inertia will be. This is because the mass of the beam is distributed over a larger distance from the rotational axis. The torque will also increase with the length of the beam, as the longer the beam, the more force is needed to rotate it.
The hinge acts as the axis of rotation for the beam. It allows the beam to rotate around it, while also providing support and stability to the beam.
External forces will cause the beam to experience a torque, which will affect its rotation. The magnitude and direction of the external forces will determine the amount and direction of the torque applied to the beam.