Wow people of all ages with this inertia penny challenge. Get kids using critical thinking skills with this fun and challenging physics activity.

Supplies

• 20 Pennies
• 1 Playing card or Index Card

Discussion about Inertia

Ask kids if they have ever heard the word “inertia”. Answers will vary depending on the age of children, but likely they will say no. Explain that inertia is a physics term that means an object at rest will stay at rest.

Use an example such as a ball sitting on the ground will remain in one place unless it is touched by another object, thus that ball at rest will remain at rest. You can build on the concept with a quick 4 minute youtube video from Make Me Genius called Law of Inertia for kids. Now that kids understand the basics of inertia challenge them to use that knowledge to complete the penny inertia challenge.

Setup the Inertia Penny Challenge

Stack 15 pennies into a tower.  Balance the playing card centered on the pennies.  Add the remaining 5 pennies making sure they line up  with the pennies below the card.

The Inertia Penny Challenge

Remove the card without moving a single penny. If done correctly the card will be removed from the stack and you will be left with a stack of 20 pennies.

Kids will try and pull or push the card out of the stack of pennies. Tell them that their is a trick. Ask them to remember that an object at rest will stay at rest.

The Trick

Flick the card! Line up your finger so you can flick the card directly centered on the edge of the card. The card will fly out leaving you with a stack of 20 pennies.

If you like this inertia activity checkout our second inertia project, Inertia Demonstration. This activity uses the same concepts to drop a penny into a cup in a seemingly magic way!