Torque And Center Of Mass Lab

Materials

1 meter stick

1 100-gram weight

A table (for use as a fulcrum)

Procedure

1. We measured the meter stick's center of mass without the weight. We determined that it was at the 49.5 centimeter mark.
2. We placed the 100-gram weight on the zero centimeter side of the meter stick and rebalanced it. The new center of mass was 29.4 centimeters.
3. The distance between the old center of mass and the new center of mass was the lever arm for the side without the weight. This lever arm was 29.4 centimeters.
4. The length from the new center of mass to the weight was the lever arm for that side. This was also 29.4 centimeters.
5. Since the lever arms were the same, the forces must have also been balanced to balance the meter stick on the fulcrum. Thus, the masses were the same, as the acceleration due to gravity is constant.
6. Since 50.5 centimeters of meter stick weighed 100 grams, then the meter stick must weigh 198.2 grams.