Materials:
  • Small coffee can
  • 1 marble
Problem:
  • How can I make the marble stay in the can while having it turned upside down and off the surface of the table?
  • The marble cannot be touched.
  • The marble must stay in the can for at least two seconds.
Procedure:
  • Place the can upside down on the surface of a table.
  • Place the marble under the can.
  • Move the can in a rapid circular motion, making certain the marble rotates around the inside of the can. While doing this procedure, lift the can straight off the table.
Solution:
Why does the marble stay in the can? Due to Centrifugal and Centripetal force, the marble remains in the can.

Centrifugal force: The force that tends to impel a thing or parts of a thing outward from a center of rotation.

Centripetal force: The force that is necessary to keep an object moving in a circular path and that is directed inward toward the center of rotation.