Toys and Physics - Sound and music

7.9 Musical box

What happens
When you turn the handle the box plays a tune.
You must turn the handle at the correct speed to hear the tune properly.

Theory and teaching notes
There are many tiny projections on the cylinder which catch on a number of metal strips. Each strip is a slightly different length and when it is twanged it vibrates giving a note.
A good example of the dependence of frequency on the size of the vibrating object.

7.10 Laughing doll

What happens
The doll makes a noise when you hit it or catch it.

Theory and teaching notes
There are a number of pre-recorded noises and each one is activated at random when the doll is hit.
An example of the conversion of kinetic energy to electricity and then sound.

7.11 Clanger

What happens
When you hit the clanger it makes a noise like the voice of a clanger.

Theory and teaching notes
The energy of the blow activates the internal circuit starting the pre-recorded sound.
A further example of the conversion of kinetic energy to electrical energy to sound.

7.12 Clangers tube (mini)

What happens
When you blow through the tube a note is produced. The pitch of the note depends on the position of the slider within the tube.

Theory and teaching notes
Small volume of air in the tube give high notes while large volumes give low note. The further out you pull the slider the lower the note.

7.13 Wooden recorder

What happens
When you blow through the tube a note is produced. The more holes you cover up the lower the pitch.

Theory and teaching notes
As with the clanger's tube the bigger the volume of vibrating air the lower the pitch of the note.

7.14 Spinning siren

What happens
The siren is first wound up and then when you pull the strings it spins and gives off a sound.

Theory and teaching notes
When you pull on the two ends of the strings the central plastic siren rotates. Air rushes through holes on the siren and so a sound is made. The faster it spins the higher the pitch of the note.
A good example of the conversion of kinetic energy to sound and the dependence of the pitch of the note on the rate of rotation.

7.15 Whistling water filled bird

What happens
As you blow into the tube the air is blown through the water and the bird makes a warbling sound.

Theory and teaching notes

7.16 Musical rolling ball

What happens
As the ball rolls a long it chimes.

Theory and teaching notes
The kinetic energy, both translation and rotation, activates the chimes within the ball.