You’ll need
- 3 coat hangers with clips – for example, skirt hangers (if you don’t have these, you can use normal coat hangers with clothes pegs as clips)
- A clothes horse (or something to hang things from)
- 4 small bags such as plastic lunch bags
- Various items to weigh, such as fruit, vegetables, toys and small household objects
What to do
- Hang a coat hanger from the clothes horse.
- From this coat hanger, hang another coat hanger at each end. Use the clips on the first hanger to stop the other ones from sliding. Take the 4 small bags and put a different item in each.
- Hold one bag in each hand and see if you can tell which item is heavier. Try this with different items.
- Now, attach each bag to a different clip on the lower 2 coat hangers.
- The heavier items will pull the side of the hanger down.
Questions to ask
Which items are heavier? Is this what you expected?
Can you find 2 items that weigh the same?
Try adding 4 more coat hangers (one at each end of the 2 lower coat hangers) and see if you can balance 8 items!
What’s happening
When a coat hanger is hanging with nothing on it, the 2 sides weigh the same. This makes the coat hanger balanced. When items are clipped to the ends of the coat hanger, the weight of each end changes. If the 2 items weigh the same, the coat hanger will stay balanced. But if one item is heavier than the other, the coat hanger will be unbalanced, with the heavy end being pulled down towards the ground.