Can you make a paper boat race across the water just by gently touching the surface of the water?
|Gently does it...|
Hypothesis (What I think will happen)
Crighton: "The washing liquid will make bubbles and push the boat along the water."
Hemani: "I think that as you touch the water gently with a little dish wash on your finger the water might get a little bubbly and it might make the water push away. Just like how I wash the dishes at home. As I put the dish wash on any plate or glass the soap starts getting bubbly."
Marcus: "I think that the dishwashing liquid would make bubbles and when the bubbles pop it would let out air and then the air will push the boat."
Bree: "I think the dish washing liquid will make bubbles and the the bubble will make wave and the boat will move."
Coloured card, washing up liquid, pencil or sharpie, scissors, large container of water.
Method (What we did)
- Drew and cut a boat shape (bird's eye view) out of the cardboard.
- Teva: "We gently put our boats on the water, and tapped the water with washing liquid on our finger."
Observation (What happened)Elijah: "When we put our fingers in the water, the boats moved."
When I did it with Room 18, the boats moved across to the other side.
Speedboat from Kieren Moriarty on Vimeo.
Conclusion (Why I think it happened)
The water surface tension is broken behind the boat. This means the surface tension is stronger in front of the boat and it pulls the boat forwards.
Short Experiment to Follow Up: Make Metal Float
Gently place a paperclip on the water’s surface.
What will happen? Will it sink or float?