Three equal point charges, each with charge 1.95uc , are placed at the vertices of an equilateral triangle whose sides are of length 0.400m . What is the electric U potential energy of the system? (Take as zero the potential energy of the three charges when they are infinitely far apart.) Use E0= 8.85×10?12 C^2/N*m^2 for the permittivity of free space.