So we are studying about springs, as of now, the assumption is that they are massless.
My teacher told me that when we extend a spring, or compress it, there is a force called the spring force which tries to reform the spring back it its original form. This force acts inwards and outwards respectively.
He also told us that the magnitude of this force is equal to the force we apply.
What I want to ask is why it this force always equal to the force we compress the spring with? Wouldn't the equality suggest that the spring will still remain deformed? If equal amount of force is coming from both sides, and if the spring is deformed then wouldnt it remain deformed?
Shouldnt the spring force be slightly greater than the external force to reform the spring?