Year 4 have had fun in their expeditionlessons this week making their own stringtelephones to find out how sound travels.
Class 13 discovered that when you talk into the cup your voice sends sound waves inside the cup, vibrating the bottom of the cup. These vibrations transfer onto the string and then travel across the string into the bottom of the other cup and into your partner’s ear.
They kept the string tight so the sound waves travelled down the string. If their string became loose, the sound wasn’t as good because the vibrations had to travel all around rather than directly down the string.
