
Wind forces on a skyscraper can set it swaying, so engineers design dampers to stop the motion and keep users comfortable. Some buildings use suspended solid mass dampers to counter a building’s motion, but others take a liquid approach. Whether by shifting water through specially shaped chambers or by sloshing it back and forth in a tank, a tuned liquid damper system can quickly bring a building back to rest. In this Practical Engineering video, Grady discusses the challenges of designing these systems and demonstrates how they work with a cool tabletop version. As a reminder, sloshing also helps in water-bottle flipping and stopping a bouncing ball. (Video and image credit: Practical Engineering)