Penny in Cup Demonstration

Penny in cup demonstration.

Set up:

Set a penny on a table or desk top. The penny should be roughly 5-8 cm from the edge of the table. Place a beaker/cup/bottle/plate/etc another 8-15 cm beyond the penny.

Introduction of topic:

Ask the students how to get the penny in the cup without touching the penny or the beaker. Try to do it with their suggestions.

Have the students try to do it without touching either object. Touching the table is okay.

Once the students have given up all hope of finding out how to do it, do the demonstration. (It works really well to do so in a nonchalant fashion) Once you do it, you can prod them to give the answer of HOW it happens.

Points to cover:

Newton’s Third Law of Motion, First Law of Motion, Bernoulli’s Principle, inquiry, scientific method, etc.

Strategy for the procedure:

Make sure to form a seal with your lips on the side of the table.

Line up with the penny directly between your mouth and the beaker.

Lift your head straight up while exhaling forcefully. (It sounds like “poo!”)

If the penny goes too far or too short, adjust the beaker as needed.

Hope it works for you! Good luck.