Today Year 4 investigated which materials absorb soundwaves. They set up an alarm in a box and covered it with various materials like bubble wrap, cotton wool, newspaper, a cotton tea towel and cardboard. They used a data logger to take a reading of the decibels from the alarm. Afterwards we analysed the data and found that all five groups decibel reading went down with the cotton wool acting as a soundproof. We concluded that cotton wool is soft and it absorbs lots of sound.
The class were great as they had to carry out the experiment in silence, using body language to communicate with their group members or else the background noise would distort the readings. They held it together really well!