Hello everyone i'm having problems figuring this out, In the quark model of fundamental particles, a proton is composed of three quarks: two "up" quarks, each having charge +2e/3, and one "down" quark, having charge -e/3. Suppose that the three quarks are equidistant from one another. Take the distance to be 1.32 10-15 m. (a) Calculate the electric potential energy of the system of only the two "up" quarks. ? eV (b) Repeat for all three quarks. ? eV Well i used the following: U_12 = [k*q1*q2]/d = [9.0e9*(2/3)^2*e]/1.32e-15 = 3.0275e24 which is wrong, any ideas what i'm doing wrong?