1. You will need 4 cups that are the same. 2. Fill each cup as follows. 1/4, 2/4, 3/4 and 4/4 3. If you have food colouring, you can add colour to each glass. 4. Gently tap each glass with a spoon. What do you notice about the sound? Why do you think that happens? 5. Can you create a musical tune? 6. a picture or video showing your musical fractions! 7. Click to submit.
In this experiment we are actually looking at the vibrating of the glass. When you hit the side of the glass with the spoon the glass vibrates. When you add water to the glass the water acts as a dampener. It causes the vibrations to slow down. When things vibrate fast they produce a sound at a higher pitch, when they vibrate slower they will produce a sound with a lower pitch. With our musical water glasses, when there is more water in the glass, the pitch of the sound produced is lower because the water has caused the glass to vibrate slower. When there is a smaller amount of water in the glass the pitch is higher because the glass is vibrating faster.