Center of Mass

How To Walk

• Write Step-by-step (no pun intended) instructions for someone to follow so that they may walk.

Activities

• Find your Center of Mass?

• Get Out Of Chair?

• Pick Up Chair?

• Leg Lift?

• Free Money?

• Post It Flip?

Definition

• “The center of mass (or mass center) is the mean location of all the mass in a system”

• Marked with:

Examples

• The center of mass of a two-particle system lies on the line connecting the particles (or, more precisely, their individual centers of mass). The center of mass is closer to the more massive object

• The center of mass of a ring is at the center of the ring (in the air).

More Examples

• The center of mass of a solid triangle lies on all three medians and therefore at the centroid, which is also the average of the three vertices.

Applications

• Objects rotate around their center of mass• In a uniform gravitational field, the center of

mass and center of gravity are the same.• A projectile’s center of mass will follow a

parabolic path.• If an object’s center of mass is outside it’s base

of support, it will topple.• An applied force that is not through an object’s

center of mass will cause rotation.