I was just notified that I won second place in the Contrived category in the 2008 AAPT Physics Photo Contest!

 

For the contest, physics students from around the world were challenged to submit a photo, either natural or contrived, illustrating a physics concept. The students were required to take the photo themselves and to write a summary of the physics occurring in the photo.

 

Check out the Contest Winners page. All of the entries this year were great. I am honored to place with them. Here is my photo and description:

 

 

Nighttime Cycloid

Named by Galileo in 1599, a cycloid is the path that a point on the edge of a circular wheel follows as the wheel moves along a straight line. A cycloid is also the solution to the Brachistochrone problem (the curve between two points that is covered by an object in the least amount of time, starting with zero speed, ignoring friction, and acting under constant gravity.)

 

Its parametric equation, assuming that the cycloid is starting at the origin, is  x=r(t-sin(t)), y=r(1-cos(t)).

 

This photo is a long exposure taken at night. I attached an LED to the edge of the tire, opened the camera’s shutter, then had my dad drive the vehicle in a straight line until it reached where I knew the edge of the frame was and stop.  In order for the vehicle to show up, I had to light up the vehicle for about 10 seconds with a spotlight.