Finding Centripetal Acceleration?

[wheeliekid]

Homework Statement

In the Bohr model of the hydrogen atom, the electron revolves around the nucleus and has a mass of 9.1 x 10^-31 kg. If the radius of the orbit of the electron is 5.3 x 10^-11 m and the electron makes 6.6 x 10^15 r/s, find

The centripetal acceleration

Homework Equations

Ac= 4pi^2 X R/T^2

The Attempt at a Solution

I know it should be 4pi^2 X 5.4 X 10^-11/ 1/6.6 X 10^15 ^2

But... the answer is 9.1 X10^ 22 and I am NOT getting the right answer. I feel like there is something wrong within my operation.

Thanks!

 

[rl.bhat]

Try this one.
Ac. = 4π²f²R
Substitute the values.