The Tower that Won't Topple (Inertia Science)

We're doing a lot of science this summer and I love it. Okay, who cares if I love it, right?!? Well, the good news is, the boys love it too.

This 5-minute experiment is impressive and inexpensive (say that tongue-twister 5 times fast!).

What You Need
10 quarters (or more/less)
a finger
a flat surface

What to Do
Stack all but one quarter in a tower on a flat surface.

Place the one remaining quarter on the same surface 3-6 inches from the tower. Now flick it across the surface using your middle finger, shooting for the bottom of the tower. (This is the hardest part as aiming can be tricky.)

What Happens
The coin you flicked slams into the bottom coin and pushes it out. Surprisingly though, the tower of remaining coins stay stacked neatly. 

How it Works
Newton's First Law of Motion (sometimes called the law of inertia) is at work. It states that an object at rest will stay at rest and an object in motion will stay in motion. The coin you set in motion stays in motion pushing the bottom coin in its path, with the stacked coins above it remain in place because they have enough inertia to prevent them from moving.