Nail Preparation

People often spend a lot of time polishing the nails supplied with a pinewood derby car kit to a mirror-like finish. But how important is this? It’s a lot of it really worth it? In this section we use an indirect experimental method to measure the affects of different kinds of nail preparation on the car’s run time. (Actually, this experiment uses an ancient device known as a “record player” to spin the wheels!) We also introduce the “Coefficient of Friction” and discuss its affects on the speed of a car. I think you’ll be surprised by these results as well.
A comparison a nails with a variety of stages of polishing.
An experiment using a turntable to test nail finishes.
Using a stopwatch to time how long a wheel will spin with different nail finishes.