Parabolic Beauty by Steven W Bao
Honorable - Contrived Category
School: Cherry Creek High School
Teacher: Jessica Olsen
If you try and set fire to a pot or a nail it won?t set on fire. However, if you set fire to steel wool, it will burn. Why? Steel wool has much more surface area than a pot or a nail and thus, a small spark from a 9V battery is enough to oxidize the steel wool, resulting in sparks, and iron rust oxide. The fine steel wool is thin enough so that the heat has nowhere to go and quickly spreads throughout the strands. This does not happen in a thicker piece of metal as thicker pieces conduct heat away too fast for the surface to reach its ignition point. In the photo, the subject is spinning steel wool around and centripetal force is demonstrated as bits of it fly off tangent to the circle. These particles act as projectiles and gravity quickly brings these bits down in a parabolic shape. The potential energy at the top of the particles? path are converted to kinetic energy as they fall and strike the ground, sometimes resulting in the particles splitting into pieces. When they strike the ground, the particles exhibit somewhat of an elastic nature, demonstrating the conservation of energy. Of course, the particles do not bounce up as high as some of the energy is lost to friction and heat. These particles once again act as projectiles, creating parabolic paths.
