$4$

Anom

Four point charges, R$,$ S$,$ T$,$ and L$,$ are located at the centers of the sides of a square, shown above. The charges have the values indicated in the figure. Each charge is held in place by an external force. Point $P$ is at the center of the square.

$($a$)$ The magnitude of the electric field at point $P$ due to charge L is $E.$ Describe the magnitude and direction of the net electric field resulting from all four charges at point $P$ in terms of $E$ and the coordinate axes shown. Briefly

$($b$)$ The magnitudes of the forces required to hold charges $R$ and T in place are $F_R$ and $F_T,$ respectively. Is $F_R$ greater than, less than, or equal to $F_T?$ Briefly justify your answer.

The configuration of charges was assembled by placing individual charges one at a time onto the square. The configuration is shown again below. The graph below shows the electric potential $V_P$ at point P as the charges were placed onto the square.

$($c$)$ In a clear, coherent paragraph$-$length response, describe the order in which the charges were assembled into their final configuration. Justify your claims by citing relevant physics principles and features of the graph.

AP Physics $2$