Easy experiment, mostly consisting of everyday supplies.
Here is all you will need for this experiment:
- two tongue depressors
- 3 rubber bands, one at least 1/4? wide
Second Step as noted in the picture below: Stack your 2 Tongue Depressors on top of each other.
Next, You will need to take one of your strips and wrap them around one end of both sticks. Be sure you keep the wrap a little loose so you can remove them after wrapping.
Then, Use a small piece of tape to tape down the end of the paper. (DO NOT TAPE TO THE STICK)
After you have completed one side, Repeat this step and do the other side so that both strips are wrapped loosely and taped. See below picture as reference.
Thirdly, Remove your taped strips. Unstack the tongue depressors. Now you need your rubberband. As shown in the picture, take your rubberband and wrap it length wise on ONE depressor.
Next Step, You will now RESTACK the Depressors. (One will be with a rubberband and the other will be without the rubberband as you see in the picture below.) Stack them on top of each other so they will look like the 2nd picture below.
Finally, After your depressors are stacked, Add your strip wrap back on each side, As seen in the below pictures. (1 wrap on each side) Then you will need the remaining 2 rubberbands. Wrap your rubberband on each side of the depressors as seen in the pictures below. (You want your rubberbands somewhat loose or your harmonica will not work properly.)
Key Concepts (courtesy Aurora Lipper)
Frequency is a measure of how many times something moves back and forth. A swing, a pendulum, a leg of a walking person all have a frequency. All those things start at one place, move, and come back to the same position that they started. This moving and coming back is one vibration. The faster something vibrates, the more frequency that something has. Frequency is measured in Hertz (Hz).
Waves are the way energy moves from place to place. Sound moves from a mouth to an ear by waves. Light moves from a light bulb to a book page to your eyes by waves. Waves are everywhere. As you sit there reading this, you are surrounded by radio waves, television waves, cell phone waves, light waves, sound waves and more. (If you happen to be reading this in a boat or a bathtub, you're surrounded by water waves as well.) There are waves everywhere!
Our ears are very good antennas. They are very effective at picking up quiet, loud, high-pitched and low-pitched sounds. It is difficult for people to make microphones that are as sensitive as our ears. Our ears can pick up and tell the difference between sounds as low-pitched as 20 Hz and as high-pitched as 20,000 Hz. Some animals can hear things that are even higher or lower pitched than that. Our ears and brain are also very good at picking out the direction a sound is coming from.