1. Tuning Forks in Water Tuning forks make sound waves we can hear
If placed in water, these waves are visible – just like waves from dropping pebbles in water
Longer tuning forks give lower frequency waves

2. Sympathetic Vibrations
Sympathetic vibrations mean that sometimes, when one thing vibrates, another will start vibrating along with it
Need to be same (have same natural frequencies)
Small wires vibrate faster (high frequency) than long ones
Pluck the long wire and only other long wire will vibrate
Pluck small wire and only other small wire will vibrate
Stationary corks on wires
Plucked long wire