# Motion Magic

You’ll stun your kids with the way a penny doesn’t move in these games, a fantastic illustration of inertia. You can give a quick physics lesson – basically, things that aren’t moving want to stay put – but whether they grasp the concept or not, they’ll be amazed by the results.

We tried out the motion magic in two ways. For the first, we cut a square of cardboard as a base (using a bit of our Kiwi Crate from the Disk Launchers set). Place the cardboard over a glass, and put a penny on top.

Quickly flick the cardboard away (from the side, not from underneath). The cardboard will fly away but the penny…

…falls in the glass! This got a whoa from Travis, who then tried himself and was so proud it worked.

There is something sort of magical about inertia, even for grown-ups. Logically we want that penny to fly away, and every time we heard the clink of the penny in the glass, we were excited.

For the second method, we cut a strip from cardstock. Form it into a circle and staple the edges.

Place the circle over the glass, with the penny on top.

Very quickly, put a finger inside the cardstock circle and flick it out of the glass. Where did our penny go?

Down inside!

Want to really up the wow factor? Try the classic trick of pulling a tablecloth out from under a plate (you might want to use a paper plate, just in case).

Is it magic? Nope, it’s inertia of course.