Three charged particles of

q$1=70\mathrm{.}0$ nC$,$

q$2=70\mathrm{.}0$ nC$,$

and

q$3=35\mathrm{.}0$ nC

are placed on the y$-$axis, as shown in the figure.

Four charged particles lie along the axes of the x y coordinate plane.

Positive charge q$1$ is above the origin.

Negative charge q$2$ is below the origin by a distance approximately equal to the distance q$1$ is above the origin.

Positive charge q$3$ is at the origin.

Positive charge q$4$ is to the right of the origin.

Charge

q$1$

has the coordinates

$(0,12\mathrm{.}0$ cm$),$

q$2$

has the coordinates

$(0,12\mathrm{.}0$ cm$),$

and

q$3$

is located at the origin.

$($a$)$

Find the electric potential energy $($in J$)$ of the configuration of the three fixed charges.

J

$($b$)$

A fourth particle, with a mass of $2\mathrm{.}071013$ kg and a charge of

q$4=140\mathrm{.}0$ nC$,$

is released from rest at the point

$(9\mathrm{.}00$ cm$,0).$

Find its speed $($in m$/$s$)$ after it has moved freely to a very large distance away.

m$/$s