Sound and vibrations 

Sound is made when something vibrates. Children should find different things that vibrate, for example rulers, rubber bands, metal hangers or the spokes of a bicycle wheel. They can be challenged to discover the factors affecting the sound produced by a rubber band or guitar strings. They will discover that the thickness, length and tension of the rubber band (or string) will affect the pitch of the note produced. They may discover that higher sounds can be made with thin, short strings and that lower sounds can be made with heavy or longer strings.