in activity you learned about center of gravity.
What is role of center of gravity with the nail balancer why don’t the overhanging nails tip the system over? Did you ever see a tightrope walker? They usually carry a low bending pole. Can you see a similarity with the nail balance? Do some research about tightrope walkers and learn What you can about the way they use center of gravity to their advantage.
Materials:
- Wood base with nail hole in centre
- Several flat-headed nails
Procedure
- This is an activity you can use to trick your family and friends. After they give up, you can show them how smart you are.
- Stand one nail (we’ll call it #1) in the hole in the board.
- Lay a second nail (#2) on the table.
- Place the remaining nails on the table with their heads over nail#2, in alternating directions.
- Lay the last nail on top of nail#2, where the nails heads overlap.
- Pick up nail#2 and the last carefully by the ends. If you have set it up correctly, the cress-crossed nails will come, too.
- Carefully balance the whole system on nail#1.
Note:
Although nails are stretching out in two directions, the fourteen nails will balance one the first nail, because the centre of gravity is at the centre of system of nails. The overhanging nails actually hold the system in balance, instead of tipping it over as one might expect at first glance. Tightrope walkers use low bending poles to help them balance for the same reason.