# Center of Mass

Written by Jerry Ratzlaff on . Posted in Relativity 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.

## Center of Mass for Two Masses calculator

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

## Center of Mass for two masses formula

 $$\large{ x_{cm} = \frac {m_1\; x_1 \;+\; m_2 \; x_2 } {m_1 \;+\; m_2} }$$

### Where:

 Units English Metric $$\large{ x_{cm} }$$ = center of mass $$\large{ ft }$$ $$\large{m}$$ $$\large{ m_1 }$$ = mass 1 $$\large{ lbm }$$ $$\large{ kg }$$ $$\large{ m_2 }$$ = mass 2 $$\large{ lbm }$$ $$\large{ kg }$$ $$\large{ x_1 }$$ = position 1 $$\large{ ft }$$ $$\large{m}$$ $$\large{ x_2 }$$ = position 2 $$\large{ ft }$$ $$\large{m}$$

## Center of Mass Multiple Masses formula

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

 $$\large{ x_{cm} = \frac {m_1 \; x_1 \;+\; m_2 \; x_2 \;+\; \cdots } { m_1 \;+\; m_2 \;+\; \cdots } }$$

### Where:

 Units English Metric $$\large{ x_{cm} }$$ = center of mass $$\large{ ft }$$ $$\large{m}$$ $$\large{ m_1 }$$ = mass 1 $$\large{ lbm }$$ $$\large{ kg }$$ $$\large{ m_2 }$$ = mass 2 $$\large{ lbm }$$ $$\large{ kg }$$ $$\large{ x_1 }$$ = position 1 $$\large{ ft }$$ $$\large{m}$$ $$\large{ x_2 }$$ = position 2 $$\large{ ft }$$ $$\large{m}$$