So, my question might seem silly. I know in real life when we apply a force with our hand and push on lets say a cylinder , we know the force will be distributed over the cross section of the area, so if we had a wider area, we need more force, and if we had smaller area, then we need less force to push the cylinder a certain distance.
So its intuitive. The stress will be the force divided by the given area.
But why? like what happens at the micro-scale, and what makes the force be divided?