A weekly feature of SideSpin.

A car travels around a one-mile oval NASCAR racetrack at exactly 30 miles per hour. Following its completion of the first lap, and without stopping, the same car continues on its way to completing a second lap. How fast will the car need to travel during the second lap in order to average exactly 60 miles per hour for both laps?

—Craig F. Whitaker

It is impossible for the car to do this. After traveling the first lap at a grandmotherly 30 miles per hour, the car would be forced off the track, the driver removed from his vehicle, dragged into the infield, and beaten to within seconds of his life. Thus, the car would never have the chance to travel the second lap at the extremely high rate of speed that would presumably be necessary to average 60 miles per hour.

A plane is standing on a treadmill. The plane moves in one direction, while the treadmill’s conveyer belt moves in the opposite direction. This treadmill has a control system that tracks the plane speed and tunes the speed of the conveyer belt to be exactly the same (but in the opposite direction). Can the plane take off?


—Stephen I. Geller

Fortunately, this is one riddle that can be solved observationally. First, we need to understand what is required in order for a plane to get airborne: namely, speed, lift and a lightweight frame. Now go to your local gym, and tell me what you see on those treadmills. I think it’s pretty obvious that plane ain’t getting in the air.

Raysism is a commenter, sinkhole surviver, runner, attorney, and lecturer who rose to fame through his listing in the Guinness Book of World Records under "Highest LSAT By A Deadspin Commenter of the Year". Since 1986, he has written "Ask Raysism", a Tuesday column in SideSpin in which he solves puzzles and answers questions from readers on a variety of subjects. If you have a question for future columns, send them to raysism@gmail.com.