• In the hydrogen atom, we consider an electron moves in a circle around the proton, with a 
   orbital radius of $5\mathrm{.}29$ x $10^-$¹¹¹ m and a tangential speed of $2\mathrm{.}18$ x $10\mathrm{⁶}$ m$/$s$.$

 

$($a$)$ Determine the centripetal acceleration of the electron.

•  $($b$)$ Determine the magnitude and direction of the net force which acts on the electron.