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Coin flick

Have you ever seen a magician pull a tablecloth off a table leaving the dishes right where they were? The science behind this display is called inertia.

Inertia is the resistance an object has to a change in its state of motion.

Here's a safe way to try this experiment without breaking mum's plates and bowls.

What to do

  1. Stack about 10 x ten cent pieces on top of one another on a table.
  2. Take one more ten cent piece and place it on the table about 10cm from the stack of coins.
  3. Coin flick experimentNow use your finger to flick the coin towards the stack of coins so that it hits the bottom coin.
  4. Wow - the coin that you flicked caused the bottom coin to shoot away but the stack of coins is still standing!

How it works

The coins all have inertia - they want to stay where they are and will resist any movement. Flicking one coin out of the stack is easy because a single coin is light and has little inertia but the stack of coins is heavy enough so that the force of another coin hitting its base is not enough to knock it over.