Pinewood Derby physics

Physics plays an important role in the design of a pinewood derby car. Here are a few areas where physics applies:

• Air Resistance
• Friction
• Potential Energy
• Rotational Inertia

Of all of these, friction and air resistance are the most well known and discussed online. These are the easiest to get right with just your intuition. But what about potential energy? Don’t all the cars have the same potential energy if they weight the same amount and are placed on the track at the same height? The answer is no! The amount of potential energy is determined by how far back your car’s center of mass is located. The center of mass is the point at which your car will balance (say on a pencil). If your car’s center of mass is located toward the front or middle of the car, you are missing out on potential energy. Potential energy is the “gas” your pinewood derby car runs on, so fill it up as much as you can. See the potential energy diagram to see the difference.