Science Experiments for Kids

Science experiments are a fun way for kids to learn all about scientific principles and the world around them. In this article, I’ll detail a few great experiments that are easy, fun, and teach your child all about the wonders of inertia.

1. Coin Shoot:

What you’ll need:
A stack of coins (at least 11)
A smooth table, or other smooth, flat surface

Step One: Stack all but one of the coins on a smooth table, making sure that the “high-rise” is straight. Make sure that all of the coins are the same denomination so that the experiment works well. I like to use nickles, because the edges are wide, making the experiment easy to do.
Step Two: Flick the extra coin sharply towards the bottom of the stack so that it strikes the bottom coin. The bottom coin from the stack should shoot out from under the other coins without disturbing the rest of the stack. With good aim, and sharp flicks of your finger, you should be able to shoot all of the coins out of the stack one by one.

Why does it work?
Because the inertia of the stack of coins is so great, the force from the single flicked coin is not enough to make the entire stack move or topple – it is just enough inertia to move the coin that is struck at the bottom.

2. The Last Pencil Standing:

What you’ll need:
A pencil
A fairly narrow strip of paper
A smooth table or other flat, smooth surface

Step One: Place the fairly narrow strip of paper on a smooth table. Hold the paper so that most of the strip hangs off of the table.
Step Two: Place a pencil on the paper so that it is standing upright. Now, slowly try to pull the paper out from under the pencil. What happens?
Step Three: Set up the paper and pencil again, but this time, try something different. Use your hand or finger to “Karate chop” the paper that is hanging off the table. The paper should move so fast this time that the pencil remains standing.
Step Four: Set up the paper and pencil one more time, and give the paper a fast, sharp pull. What happened to the pencil this time?

Why does it work?
Since a body (in this case, the pencil) at rest wants to stay at rest (its original state of motion), the pencil will resist the fast motion of the paper. This means that when the paper is moved rapidly out from under the pencil, the pencil remains standing upright. If the paper is moved slowly, the motion has a chance to affect the pencil, and it will topple.

3. Coin in the High-rise:

What you’ll need:
6 dice
A coin (I like to use a quarter for this experiment)
A pen or a nail file

Step One: Build a column out of the six dice.
Step Two: Put a coin (I like to use a quarter, or similarly sized coin) in the middle of the column so that there are three dice below the coin and three dice above the coin.
Step Three: Put the point of a pen, or the narrow side of a nail file, on the side of the coin, and give the pen or nail file a sharp tap. The coin should shoot out of the dice stack without disturbing the dice or knocking over the high-rise.

Why does it work?
The force and movement from your hand tapping the pen (or nail file) is transferred immediately to the coin. However, the movement is not transferred to the dice because of the low friction. The dice have a fairly large inertia, due to their weight, so they stay upright and undisturbed even after the coin flies out from the middle of the dice column.