# Center of Mass Problem

by sweatband
Tags: mass
 P: 16 1. The problem statement, all variables and given/known data Consider a system of two blocks that have masses m_1 and m_2. Assume that the blocks are point-like particles and are located along the x axis at the coordinates x_1 and x_2. In this problem, the blocks can only move along the x axis. Find the x coordinate of the center of mass of the system. 2. Relevant equations The solution is ( $$\((m1x1 + m2x2)/(m1 + m2)$$, but I cannot for the life of me understand why this is exactly. Why multiply the mass by the x-coordinate of its location? 3. The attempt at a solution
 Sci Advisor HW Helper P: 4,738 What is the general formula / definition of center of mass ?
 Mentor P: 41,477 Are you questioning the definition of center of mass? Maybe this brief discussion will help: Center of Mass
 P: 16 Center of Mass Problem Center of mass: The point that represents the "average" position of the entire mass of a system.
HW Helper
P: 4,738
 Quote by sweatband Center of mass: The point that represents the "average" position of the entire mass of a system.
well hmm yes and no, i meant: formulate it with an expression.
See the link that Doc Al posted.
 P: 16 What I don't understand is the algebra of arriving at that equation, and thanks for that link, Doc Al, I'm looking over it now
HW Helper
P: 4,738
 Quote by sweatband What I don't understand is the algebra of arriving at that equation, and thanks for that link, Doc Al, I'm looking over it now

Well the thing is that the definition is purley mathametical, and trying to explain it in words are just secondary. The definition of center of mass is the formulas that is posted on that link.
 P: 16 Awsome, the link answers my all my questions, thanks guys!