Springs are a unique object in physics. Springs have their own set of equations for different physics concepts. Let's look at a few background concepts that are required to understand the spring equations.

One such concept is spring equilibrium. We all know that springs can be stretched and compressed. That's what makes them very fun to play with. However, springs are at equilibrium when they are neither stretched and compressed and just left alone. Now, back to stretching and compressing, whenever the spring is stretched or compressed, a certain distance represented by x from the equilibrium point, a force is produced. You can feel this force as sort of a tension whenever you compress or stretch it. The equation for this spring force is F=-kx, where x is the distance from the equilibrium point, and k is a number known as the spring constant. The negative sign is to show that spring force is a restoring force. This means that the spring force points in the opposite direction of a force such as a box being pushed on a spring, to try to restore the spring into equilibrium. The spring constant is a very special number that determines the spring's stretchiness, how hard you need to push or pull to stretch or compress the spring. The vital thing to know about spring force is that if you were to suddenly just let go of the spring from its stretched or compressed state, as the spring is returning to its equilibrium state, the spring force is decreasing at every instant until it goes back to zero.

Potential energy is another concept that applies to springs. Imagine if you were holding any object compressed against a spring, such as marble. If you were to let go, the spring would propel the marble forward. This means that the spring must be doing some work on the marble. Therefore, energy has to be involved here. The equation for potential energy is Us=(½)kx^2 where like before, k represents the spring constant, and x represents the distance from the equilibrium position. This equation works with the concept of Conservation of Energy as well as any object that is initially pressed against the spring would have kinetic energy as soon as it leaves it. Now, you know precisely why springs are as fun as they are.