Mass of a Meter Stick Challenge

Our goal was to find the mass of a meter stick using only a meter stick and a 100g weight.
In order to do this, we placed the weight on the very end of the meter stick and then balanced the meter stick on the edge of a table. When something is balanced, it means that its clockwise and counterclockwise torques are balanced. Because torque = force x lever arm, the force x lever arm of the right side equaled the force x lever arm of the left side.
On the left side we have the 100g weight. The force of this will be the mass of this weight multiplied by the force of gravity, 9.8. The force on the left is 980. The meter stick was balanced at the 30 centimeter point making the lever arm 30 cm.
On the right side, we do not know what the force is. The lever arm is from the point of balancing to the center of gravity of the entire stick which is at 50 cm. The lever arm of the right is 20cm long.
Our equation is 980 x 30 = x x 20. We solved using algebra to get...
1470. the decimal point must be moved over to convert it back into grams.
The mass is 1.47g.

Center of gravity + torque

Although the Leaning Tower of Pisa is leaning it does not fall down. This is because the tower's center of gravity is over, or within the base of support. Center of gravity is when gravity acts on a center of mass. The center of gravity is the average position of mass in an object.
In the picture below, the pink dot is the center of mass, the pink line is the center of gravity and the green is the base of support.  Although the object is leaning it is not falling over because its pink center of gravity is within the green base of support. In the second picture the pink center of gravity is not within the green base of support. Therefore the object will have a blue force resulting in an orange lever arm. A lever arm is the distance from the axis of rotation, or where the object rotates from. When something falls it rotates. In order for something to fall, torque is required because it causes rotation (torque=forcexleverarm). In order to have a large torque, the object must have either a large force or a large lever arm or both. The larger the torque, the larger the rotation. In the situation below, the object falls because its center of gravity (pink) is outside the base of support (green), has a lever arm (orange), and therefore has a torque which causes the object to fall.