Our team put ballons full of air in the water and then pubtured it using a knife. As can be seen in slow-mode, the air deformated under water pressure.
Team First Report
Experiment by: Chase Clevelana, Joe Ryan, Morgan Benninger, Ziwei Zhao.
Our team conducted an experiment that observe the flow of gas under water pressure. We recorded the experiment result by slow motion camera under natural light. The experiment was carried out in a fish tank. We put the air-filled balloon into the water, applying a vertical downward force directly above the balloon, and recording the moment of the balloon exploded.
As shown in the video, the gas in the balloon retained the shape of the balloon at the moment of the explosion, and then the gas particles were subjected to forces in different directions and move in different directions. The buoyancy formula of a gas particle can be expressed as:
The direction of the force of the gas particles at different positions is not the same. The closer the gas is to the bottom, the greater the upward buoyancy force in the vertical direction. Similarly, the closer the gas is to the top, the greater the downward buoyancy force. So the deformation of the gas showed like the shape of the mushroom.
The video also contains an experimental record showing the fluid phenomenon of intermittent bubbles rising to the water surface. In the video, we can clearly see that the air spilling out of the balloon speeded up when it got close to the previous air bubble. This is because when the bubble approaches the previous bubble, the water pressure around it decreases, causing its velocity to increase.
To make this video, we used balloons in different shapes and sizes for the best visual effect. We used natural light for lighting. We also eliminate reflections by adjusting the position of the shade cloth. The device we use is iPhone7 with 1080p, 120 fps, which has good hardware conditions to help us complete the shooting.
We tried to add food coloring in the experiment to get better visual effect. In the experiment, the power of the balloon explosion was greater than we expected. The change in air pressure caused the camera to vibrate, which made the video more shocking and interesting. Through this experiment, we have consolidated our knowledge about water pressure. I am very satisfied with this experiment.