Problem $5$

$($a$)$ Calculate the electrical potential $($voltage$)$ created by a uniformly charged ring of radius R at a point P on the z axis. Give your answer in terms of the radius R of the ring, the height z of point $P$ and the charge $Q$ of the ring.

$($b$)$ Calculate the voltage at the point $P$ given that $Q=-6\mathrm{.}0nC,R=5\mathrm{.}0cm$ while $z=10\mathrm{.}0cm.$

$($c$)$ A proton, initially at rest, is released from point $P.$ Calculate its speed when it arrives at the center of the ring.