# Center of Mass

Center of mass or center of gravity is a specific point in a system in reference to a mass. The center of mass of a rigid object is a fixed point in relationship to the mass.

## formula

A system at a specific time, on the same axis, having two masses.

\(x_{cm} = \frac {m_1 x_1 \;+\; m_2 x_2 } {m_1 \;+\; m_2} \)

Where:

\(x_{cm}\) = center of mass

\(m_1\) = mass 1

\(m_2\) = mass 2

\(x_1 \) = position 1

\(x_2\) = position 2

## formula

A system at a specific time, on the same axis, having multiple masses.

\(x_{cm} = \frac {m_1 x_1 \;+\; m_2 x_2 \;+\; \;\cdots } { m_1 \;+\; m_2 \;+\; \;\cdots } \)

Where:

\(x_{cm}\) = center of mass

\(m_1\) = mass 1

\(m_2\) = mass 2

\(x_1 \) = position 1

\(x_2\) = position 2