Four charges are placed at the four corners of a square of side 15 cm. The charges on the upper left and right corners are +3 μC and -6 μC respectively. The charges on the lower left and right corners are -2.4 μC and -9 μC respectively. The net electric force on -9 μC charge is:

Question

a. 5.1 x1011 N/C away from the proton
b. 5.1 x1011 N/C toward the proton
c. 5.1 x1010 N/C toward the proton
d. 5.1 x1010 N/C away from the proton

Answer 1

is it towards the proton?

Answer 2

I think it will be away from the proton...

I didn't do the math.