to as little as 1 g by removing material from the inside of the wheel. A raised wheel can reduce the rotational energy up to one-quarter, but this advantage is less with a bumpy track. Another consideration is the track itself. A track that is mostly sloping, with little flat at the end, can allow cars with minimal mass in their wheels to shine. However, a track with a steep slope and then a long flat section can penalize such cars due to the quick loss of energy they experience once they have reached the bottom, when all potential energy has been transferred to kinetic and rotational energy. Such cars will take a lead on the downslope, but may be passed by cars with more energy "stored" away as rotational energy on the flat. A proper lubricant, typically graphite powder, is essential. Wheel alignment is important both to minimize wheel contact with the axle head and body as well as to limit the contact between the wheels and guide rail as the car travels down the track. There are 32 friction causing surfaces on a pinewood derby car. These include the surfaces of all four wheels which touch either the axle, the body or the track and the surfaces of all four axles which touch the wheel. Neglecting to polish and lubricate any of these 32 surfaces will result in degraded performance. The center of mass of a typical car is low and slightly ahead of the rear axle, which helps the car track straight as well as providing a slight advantage due to the additional gravitational potential energy. Legacy The pinewood derby was selected as part of "America's 100 Best" in 2006 as "a celebrated rite of spring" by Reader's Digest. The event has also been parodied by South Park in the episode "Pinewood Derby" and in the film Down and Derby. Gallery See also F1 in Schools CO2 dragster References External links Boy Scouts of America Racing Recurring sporting events established in 1953 Scouting events Toy cars and trucks Wooden toys 1953 establishments in California