Ping pong balls inside of beakers
Beakers with water and ping pong balls on a scale
Beakers with water and ping pong balls on a scale

 

Code Number: 2B40.57B

Demo Title: Buoyancy Paradox - 3 Beakers & Density Balls

Condition: Excellent

Principle: Comparison of Weights and Densities

Area of Study: Fluids

Equipment: 

Three Beakers, Two Ping-Pong Balls, Two Super Balls, and Scale.

Procedure:

Fill one of the 3 beakers with 800ml of water. Drop the two ping-pong balls into a beaker and fill it to an 800ml level. Do the same with the remaining beaker and two super balls. When you position any of the two beakers on the scale, they should balance.

NOTE: The final adjustments in volume can be made using a water bottle.

References:

  • Paul Hewitt, "Answer to April Figuring Physics", TPT, Vol. 58, #5, May 2020, p. 358.
  • "Hydrostatic Paradox", Pike's Illustrated Catalogue of Scientific & Medical Instruments, 1984, p. 237.
University of Maryland Physics Department QOTW Question #3
University of Maryland Physics Department QOTW Answer #3
University of Maryland Physics Department QOTW Question #306
University of Maryland Physics Department QOTW Answer #306