When a spring is stretched or compressed, it stores energy in the form of 1) potential energy. The amount of energy stored depends on the spring's stiffness, also known as the 2) constant, and the distance it is stretched or compressed. The formula for elastic potential energy is 3), where E is the elastic potential energy, k is the spring constant, and x is the extension or compression of the spring from its natural length.

Elastic potential energy is a form of mechanical energy and is stored in objects that are stretched or compressed. When a spring is stretched, the force required to do this is proportional to the 1), according to 2) Law. This means that the greater the extension, the more force is needed to stretch the spring further. However, this relationship holds true only up to a point, beyond which the spring reaches its 3)  limit and may deform permanently.

Elastic potential energy can be transferred to other forms of energy. For example, when a stretched spring is released, its stored energy is converted into 1) energy as the spring returns to its original shape. This principle is often seen in objects like trampolines, slingshots, and rubber bands. The stiffer the spring (i.e., the larger the spring constant), the more 2) is required to stretch it, and the more energy it can store for later use

1. A spring is stretched by 0.75 meters and stores 9 kJ of elastic potential energy. Calculate the spring constant of the spring. Use the correct equation on the right.  Answer N/m

2. A bungee cord behaves like a spring and is stretched by 1.5 meters. The energy stored in the stretched cord is 13.5 kJ. Calculate the spring constant of the bungee cord. Answer N/m

3. A trampoline acts like a spring and compresses by 0.4 meters under the weight of a person. The elastic potential energy stored in the trampoline is 2.4 kJ. Calculate the spring constant of the trampoline. Answer K = N/m

4. A car suspension system compresses by 0.1 meters under the load of the car and stores 500 J of elastic potential energy. Calculate the spring constant of the suspension system. Answer K = N/m