Centre of Gravity

Every object has a spot that is called the centre of gravity. Try this experiment to find the centre of gravity of a ruler.

What You Need

What You Do

1. Balance the ruler on your finger. (Move your finger right or left to find the spot where the ruler balances.) This spot is the ruler’s centre of gravity.
   
2. Mark the centre of gravity with a small piece of masking tape. Write “3 cm” on the masking tape.
3. Place an eraser 3 cm from the end of the ruler and tape it in place.
   
4. Repeat steps 1 and 2. This time, mark the centre of gravity with a piece of masking tape with “6 cm” written on it.

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Show What You Know!

Complete some questions about the reading selection by clicking “Begin Questions” below.