\begin{problem*}{23.62}
Four identical charged particles ($q=+10.0\U{$\mu$C}$) are located on
-the corners of a rectangle as shown in Figure P23.62. The dimensions
+the corners of a rectangle as shown in Figure~P23.62. The dimensions
of the rectangle are $L=60.0\U{cm}$ and $W=15.0\U{cm}$.
Calculate \Part{a} the magnitude and \Part{b} the direction of the
total electric force exerted on the charge at the lower left corner by