23 August 2015
The Physics of Road Runner
The classic Warmer Brothers cartoon featuring Wile E. Coyote and the Road Runner involved the repeated attempts by the hapless Coyote to capture a Road Runner bird, involving a range of increasingly outlandish contraptions, that without fail, backfired spectacularly. Wile E. Coyote frequently attempted to use rockfalls in various guises as a device to ensnare the Road Runner. I came across two notable examples on YouTube:
1. The Rolling Boulder
Pushing a rolling boulder down a slope to catch the fast-moving Road Runner is a challenge of timing:
Wile E. Coyote clearly underestimated the long runout effect of some large landslides, such as rock avalanches. Mind you, the friction coefficient of this boulder would be a challenge for even the most seasoned landslide specialist.
2. The rockfall
In this case Wile E. Coyote tries to catch the Road Runner with a classic rock topple, with a nicely placed keystone:
Even though Wile E. Coyote has modeled the system, he demonstrated here that predicting the likely behaviour of any rockfall is difficult, especially when the blocks are irregular in shape!
I am very glad I don’t have to try to understand and forecast landslide behaviour in cartoon land!