Once we collect our data, namely displacement and velocity, we can use several equations to determine the potential energy. The first step to finding the potential energy is to find the kinetic energy of both carts as they move away from each other. The equation we will use is the equation we discussed in class: Kinetic energy= .5(m•v^2). Once we have the kinetic energy for both carts, we can add the two together to get the Total Mechanical Energy. Since this is a closed system, the Law of Conservation applies, which means that energy cannot be added. Additionally, the Law of Conservation tells us that the total kinetic energy of the moving carts is equal to the potential energy of the plunger before it releases. Using all of these steps, we are able to figure out just how much potential energy is stored in the plunger of the cart.