Question

Four point charges are located at the corners of a square that is 8.0 cm on a side. The charges, going in rotation around the square, are Q, 2Q, ?3Q, and 2Q, where Q = 5.5 muC (See the figure). What is the total electric potential energy stored in the system, relative to U=0 at infinite separation?

Four point charges are located at the corners of a square that is 8.0 cm on a side. The charges, going in rotation around the square, are Q, 2Q, ?3Q, and 2Q, where Q = 5.5$\mu$C (See the figure).

What is the total electric potential energy stored in the system, relative to U=0 at infinite separation?

Answer 1

U = k(Q)(2Q)/a + k(Q)(2Q)/a + k(2Q)(-3Q)/a + k(Q)(-3Q)/(a*sqrt(2)) + k(2Q)(-3Q)/a + k(2Q)(2Q)/(a*sqrt(2)) + k(2Q)(-3Q)/a

(given U at inf = 0)

U = kQ²/a [2 + 2 - 6 - 3/sqrt(2) - 6 + 4/sqrt(2) - 6] = -kQ²/a [14 - sqrt(2)] = -42.83 J

Cheers

PS - Fell free to ask any doubbt

Answer 2

ert a Ka,a B+al f。lenda al Ernurga gloredin.a.plen. L. レ

u=[(-8) (9x10⁹)(5.5x10^-6)²/8x10^-2]+[(9x10⁹)(5.5x10^-6)²/($\sqrt$2 * 8x10^-2)]

U=-24.8 J