2a10.05.jpg

 

Code Number: 2A10.05

Demo Title: Surface Tension - Pennies in a Cup

Condition: Excellent

Principle: Surface Tension

Area of Study: Fluids

Equipment: 

Clear plastic cup, Water, Pennies.

Procedure:

Fill a plastic cup to the very top so that there is a visible meniscus showing above the rim of the cup.  Start dropping pennies into the cup.  See how many pennies it takes before the water spills out of the cup.

References:

  • Robert Ehrlich, "H.16, Dropping Pennies into a Water-Filled Cup", Turn The World Inside Out, p. 110.
  • Bobby Mercer, "Super Wet Penny", Junk Drawer Chemistry, 2016, p. 32.
  • Tik L. Liem, "How Many Pennies Can Go In", Invitations to Science Inquiry - Supplement to 1st and 2nd Ed. p. 44.
  • Julius Sumner Miller, Q126 & A126, Millergrams II – Some More Enchanting Questions for Enquiring Minds, p. 18 & 80.