Three charges are at the corners of an isosceles triangle as shown in Fig. E21.55. The $\pm 5.00 \mu \mathrm{C}$ charges form a dipole.
(a) Find the force (magnitude and direction) the $-10.00 \mu \mathrm{C}$ charge exerts on the dipole. (b) For an axis perpendicular to the line connecting the $\pm 5.00 \mu \mathrm{C}$ charges at the midpoint of this line, find the torque (magnitude and direction) exerted on the dipole by the $-10.00 \mu \mathrm{C}$ charge.