Vibrations and Waves

All these facts are to do with VIBRATIONS of one type or another. A vibration is a wobble, either from side to side or up and down.
In Physics we also call it an OSCILLATION.

MECHANICAL VIBRATIONS

The following is a list of mechanical vibrations that you can easily try in the lab. For each experiment try to find out what affects the RATE of vibration.
1. Put a ruler over the edge of the bench and twang it.
2. Blow into a wooden organ pipe
3. Run your fingers round the top of a wine glass (clean them with meths first)
4. Fix a weight to a spring and then let it oscillate up and down
5. Play a saw with a bow (the side without the teeth!)
6. Make a simple pendulum with a mass on the end of a string
7. Play any stringed instrument
8. Fix a trolley on the bench between two supports using springs. Make the trolley oscillate.
9. Lay a slinky spring on the bench and vibrate one end
10. Half fill a plastic tank with water and move a wooden plunger up and down in it.

The RATE of vibration is called the FREQUENCY and is measured in HERTZ.

A frequency of 1 Hz is a rate of vibration of ONE oscillation per second. To measure high frequencies we use kilohertz (kHz) (1 kHz = 1000 Hz) and megahertz (MHz). [1 MHz = 1 000 000 Hz].
You may have met frequency scales before - on a piano or on a radio. The frequency of middle C is 256 Hz and that of FM radio about 100 MHz.

The experiments suggested on this page should have shown you that: