Engineers Week 2020 has been running nationwide from 29th February to 6th March 2020. The children in 2nd and 3rd have been taking part and explored activities related to their project on communications.
Paper Cup Telephones
The children saw that sound is a form of energy and it travels in waves.
Speaking into the cup creates sound waves which are converted into vibrations at the bottom of the cup. The vibrations travel along the string and are converted back into sound waves at the other end so your friend can hear what you said. The children discovered that when they pulled the string taut they could hear each other well in the plastic cups but when the string was slack they could not hear what the other person was saying.
Sound travels through the air but it travels even better through solids such as your cup and string, allowing you to hear sounds that might be too far away when traveling through the air. We also tested how sound could travel better through your finger and table than through air!