Three mass points m_(1)m_(2) amd m_(3) are located at the vertices of an equilateral triangle of length a. What is the moment of inertia of the system about an axis along the altitude of the triangle passing through m_(1)?

Three mass points m_(1)m_(2) amd m_(3) are located at the vertices of

1.	Three mass points m_(1)m_(2) amd m_(3) are located at the vertices of an equilateral triangle of length a. What is the moment of inertia of the system about an axis along the altitude of the triangle passing through m_(1)?
Answer» Solution :`I= UNDERSET(i=I) overset(N) SUM m_(i)r_(i)^(2)` `=m_(1)xx0+m_(2)xx(BD)^(2)m_(3)xx(DC)^(2)` `=0+m_(2)((a)/(2))^(2)+m_(3)((a^(2))/(2))` `I=(1)/(4)(m_(2)+m_(3))a^(3)`