DL-Simple Harmonic Motion

Demo - Mass on a spring.  I put a flat piece of cardboard on the bottom, and hang a 1 kg mass on one of the springs.  I put a Vernier Rangefinder under it, and show the graphs of position, velocity, and acceleration.  You can make the graphs start so that the position graph is a Sine graph, and show that the velocity is Cosine, and the acceleration is negative Sine. 

You can make the position look like a Cosine, and then the velocity is negative sine, and the acceleration is negative cosine.

Demo - Resonance - The classic resonance boxes - I like to de-tune one so it doesn't work, and then tune the other one to match, and then they work again.  Radio broadcast uses this principle - the LC circuit in a radio resonates to the carrier frequency.

Demo - Wiggler on a Post - I attach a motor with an off center cam (A vibrator) to a variable power supply and show the resonant frequency - how the amplitude goes crazy.  I then show the coupling phenomenon - how it wants to stay in resonance.  I talk about washboard roads.  You can either go slower than the resonant frequency, or faster - you can show the amplitude curve.

Demo - Singing to a Guitar/Banjo/Piano - Sing into the instrument at the same pitch as the string is tuned to.  The instrument magically resonates and plays the note.  I point out that this is how an orchestra tunes, and it doesn't have to be the same note, it can be a consonant interval like a fifth, and it still works.

Demo - Wine Glass - I put a bit of water in a wine glass and make it sing by rubbing my finger on it.  Bowing a string is a similar concept.

The Bay of Fundy - Water in a cup - slosh it back and forth at different tempos.  You will know when you hit the resonant frequency

Demo - stuff

Lab - stuff