BAM - Periodic Motion

Here is a brief video giving some guidance about the B assignment for periodic motion, in particular question 3.

   

Although this is a repost from my twitter stream, it illustrates the difference in period between pendulums in a beautiful way.

This professor helps to explain resonance and then gives a wonderful simple demonstration. He does some calculation practice for pendulums first as well. Note that in his calculations he is solving for FREQUENCY instead of PERIOD. This means that his formula is flipped upside down compared to ours. The demo he uses is a great illustration of resonance!

Behold the power of resonance! This is video of the Tacoma-Narrows bridge from the 1940's. Every object (pendulum, rocking chair, slinky, even bridge!) has a natural frequency, or rate at which it prefers to vibrate. If you help push it just right (resonance) you can get an effect like this.