In this activity, your task is to use balanced and unbalanced forces to balance a pencil vertically on a craft stick. Every object with mass has a center of gravity. The center of gravity is the point on an object where the mass is perfectly balanced. The ease with which an object can be balanced depends greatly on the location of its center of gravity. In a pencil, the center of gravity is right in the middle.

Of course, it is much easier to balance an object with a broader base of support and a lower center of gravity. In our activity, the base of our object is the tip of the pencil – not very big. Since we cannot make the tip of the pencil bigger, we have to move its center of gravity. To do this, we attached the pipe cleaner with the clothespins and added mass to move its center of gravity and increase its stability.