What is the definition of Center of Mass?
The average position of all the mass in an object or system; the balance point.
What does center of mass represent?
The mean position of every section of the object or system, weighted by mass.
How to calculate the Center of Mass for a System of Discrete Masses?
Use the formula: $$ X_{cm} = \frac{m_1x_1 + m_2x_2 + ... + m_nx_n}{m_1 + m_2 + ... + m_n} = \frac{\sum_{i=1}^{n} m_ix_i}{\sum_{i=1}^{n} m_i} $$.
