Subtitles section Play video Print subtitles - I think it's time we the scientifically challenged and concentrate on one of science's heroes, Tyler Bradt, kayaker extraordinaire. He wants to kayak over this, Palouse Falls in Washington. Thousands of cubic feet of water pass over this fall every second and drop 186 feet to the pool below. To consider kayaking over this, he must either be a few sandwiches short of a picnic, or a world record breaker. We hope. [music playing] Oh. There he is, the new world record holder of one of the most dangerous stunts I have ever seen. Needless to say, even if you do have a 186-foot water feature, don't try this at home or anywhere else. Falling off a waterfall is the easy part. But as gravity initially accelerates you down at 32 feet per second per second, it's surviving that's the tricky bit. Our kayaker must go over the falls at the correct speed to give gravity just enough time to generate the angular velocity needed to rotate the kayak 90 degrees. This angle minimizes hydrodynamic drag, so he experiences less impact force and cuts through the water. It's also worth noting that a kayak's stability is dependent on keeping the center of mass in line with the center of buoyancy, which is in the middle of a submerged volume. Otherwise. OK. Science-taught, let's see if our team of want-to-be record breakers have learned. He's practicing the science with a man-made kind of waterfall, but the law of gravity is the same. The thin layer of water acting as a lubricant combined with the steep angle allows gravity to do its thing. It's not quite the 32 feet per second per second of a waterfall freefall, but he's only practicing. On to angular velocity, or in this case, the lack of it. Launching too fast meant he gained very little angular velocity, hitting H2O at a terrible angle, thereby maximizing hydrodynamic drag. Which is bad, as it brought him to an almost immediate and very painful stop. Waterfall. Check. Angular velocity. Check. Stability. Check, ish. It's an upside down check, but technically he still got himself into a stable position. It's just a shame his center of mass is directly below his center of buoyancy, as his head is the thing he uses to breathe. Cheering without acknowledging the person that just saved your life. Check. Even if our want-to-be record breakers do get to grips with angular velocity, hydrodynamic drag, and stability, like Tyler did, 186 feet is just too dangerous. Maybe it's better to kayak somewhere safer, like a puddle.
B2 angular velocity waterfall kayak gravity stability Kayaking Over a Waterfall | Science of Stupid: Ridiculous Fails 15 1 林宜悉 posted on 2020/10/23 More Share Save Report Video vocabulary