Centripetal acceleration of electron

[lovemake1]

Homework Statement

In the Bohr model of the hydrogen atom, the electron revolves around the nucleus. If the radious of the orbit is 5.3x10^-11 m and the electron makes 6.6^13 r/s find

a)the acceleration of the electron and
b)the centripetal force acting on the electron. (this force is due to the attarction between the positively charged nucleus and the negatively charged electron) The mass of the electron is 9.1x10^-31

Homework Equations

ac = 4pi^2rf^2

The Attempt at a Solution

im not quite understanding part a). its asking for the acceleration of the electron but how can you find acceleration ? isn't it centripletal acceleration?
could someone direct me in the right direction ? do i use ac = 4pi^2rf^2 ?

 

[rock.freak667]

yes it is asking for the centripetal acceleration, a_c which is given by

a_c=\frac{v^2}{r}=v\omega = \omega^2 r