F = ma. F also = kx. If I were to push a spring stuck vertically to the face of a surface to the same extent (assuming I could accurately control the force exerted by my muscles) at different speeds, how would I calculate the Force exerted by me in these two different situations?
If an object experiences two forces of magnitude F in opposite directions, why is the stress not equal to 2F/A? What if there's only one force F?