Water Hammer

water hammer


  •  The water-containing flask has been partially evacuated, allowing the water inside to fall as one solid column. (Typically water breaks up as it falls through air, due to drag.) The sound made when the water hits the bottom is quite remarkable.
  • To use: hold the flask vertically with the bulb at the top. Quickly shake the flask up and down once. When the water hits the bottom it sounds (and feels!) more like a solid metal object than a fluid.  In fact, I’m convinced that the flask would break if shaken hard enough, though the information sheet doesn’t caution against it.
  • Located in L02, section D1.


Hammer Balance

hammer balance

hanging hammer 1


hanging hammer 2

  • Hammer balances in a manner that appears impossible, but does so because 1) center of mass is not beyond edge of table, and 2) angular displacement of hammer increases potential energy of system, meaning system is stable. Stick end can be pushed very close to table edge, as seen in above photo.
  • Demo located in L02, section B4