In this blog I will write about the internet phenomenon known as the water bottle flip. This action gained popularity in high schools and colleges around the world, and national talk shows, and even in the NBA! It's time to analyze the physics behind the so appealing flip.
First of all, most of the bottles being flipped have a lower amount of water in them. They are certainly not full, about 1/3 to 2/5 full to be exact. This lowers the center of gravity, and therefore makes it easier to land the bottle. A higher center of gravity in a full water bottle would make the bottle want to tip over as the force of gravity is stronger and further from the surface. Secondly, when you flip the water bottle, based on angular momentum, the bottle will continue to rotate as result of inertia. However, the nonuniform water at the bottom of the bottle has a resistive net force down, and therefore a net torque that will cause the bottle to decelerate. As result, the bottle slows down when it reaches its upright position and has a great chance of landing opposed to a full bottle of water where the force of gravity is uniformly distributed.
Finally, I will show you the video that started this whole bottle phenomenon. It is intense.