Caption: Center of mass calculated for objects along a line.
Features:
x_cm = ∑_i (m_i*x_i) / ∑_i m_i
   
   
 
= ∑_i (m_i*x_i) / m ,
where m_i are the masses of the objects, x_i are centers of mass of the objects, and where m = (∑_i m_i) is the total mass of the system.
vec_r_cm = ∑_i (m_i*vec_r_i) / ∑_i m_i
       
       
 
= ∑_i (m_i*vec_r_i) / m ,
vec_r stands for position vector in a klutzy html notation.