I am looking at center of mass equation. The law of the lever says that given masses m1,m2...m_n, with respect signed distances x1,x2..x_n, the lever will balance if the sum of the moments = 0. Can someone prove this using physics.
Furthermore, please explain xbar. It says that given m1,m2.. at points x1,x2.. from a ref. point , then the system will balance if Sigma xi*mi - m*xbar= 0 I dont understand this,

Question

I am looking at center of mass equation. The law of the lever says that given masses m1,m2...m_n, with respect signed distances x1,x2..x_n, the lever will balance if the sum of the moments = 0. Can someone prove this using physics. 
Furthermore, please explain xbar. It says that given m1,m2.. at points x1,x2.. from a ref. point , then the system will balance if  Sigma xi*mi - m*xbar= 0  I dont understand this,

anonymous · Answer

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