Length of rubber band determines pitch | Sound | Physics

Have you ever wondered why the strings in a piano are of different lengths? In this activity we see how the frequency or pitch of a wire depends on its length. Take a box and stretch a rubber bad around it as shown in the video. Put two pencils beneath the band and listen to the sound produced on plucking the band. Keep increasing the distance between the pens and listen to the sound produced each time. You will notice that at the shortest length the sound is sharp and as the length increases the pitch becomes lower. In musical instruments, we either have strings of different lengths (piano, harp) or use our hands to change the length of the strings (guitar, violin) and thus produce sounds of different pitches.