Beginning Math and Physics for Game Programmers

Potential Energy and the Conservation Law

Now that we've defined work and kinetic energy, there's one more type of energy to define before we can tackle another formula for modeling motion. That energy is called gravitational potential energy (GPE). Basically, GPE is the energy stored in an object due to its height off the ground. If you picked up this book and held it in the air, it would have gravitational potential energy. How do you know that energy is stored in the book? Just let go. Did the book move? Sure—it fell to the ground because of gravity. This tells you that potential energy was stored in the book until it was released.

How do you measure the amount of energy stored in that book? Well, it's based on the object's mass and, most ...