Where is your centre of gravity?

Materials needed

• · Pencil or other small objects

Procedure

1. Put your pencil on the floor.
2. Standing near the pencil, pick it up without bending your legs or moving your feet.
3. Stand against the wall, with your heels touching the wall.
4. Drop your pencil on the floor near your feet.
5. Bend over and pick up your pencil without moving your feet or bending your legs. You must also not lean against anything or hold onto anything for support.
6. What happened? Why?
7. Repeat steps 1 and 2. Notice your movements as you pick up the pencil. Explain what happened in step 5 in terms of the effect of the centre of gravity.

For problem solvers: 

try this activity with family members and friends.try replacing the pencil with a coin or with a dollar bill. Can you find anyone who can pick up the object without breaking the rules?

Teacher information

Any time we are on our feet, whether we are walking, running, standing, or bending overawe are constantly adjusting to the centre of gravity in order to remain “balanced”. The body makes these adjustments so automatically that we don’t think about them.
The “for problem solvers” section invites students to try this activity with family members. Replacing the pencil with a dollar bill and offering it to the person who can pick it up without breaking the rules will increase interest and effort substantially. The money is as safe as if it were behind lock and key.