need help with promblem d, I think I have the correct formula for this example.

Given data:
* The centripetal acceleration of the system is,
[tex]a=2.5ms^{-2}[/tex]* The radius of the circular motion is r = 1.5 m.
Solution:
The centripetal acceleration in terms of the linear velocity is,
[tex]a=\frac{v^2}{r}\ldots\ldots(1)[/tex]The linear velocity of the body in circular motion is,
[tex]v=\frac{2\pi r}{T}\ldots\ldots(2)[/tex]Substituting the value of velocity from the (2) equation to the (1) in the equation,
[tex]\begin{gathered} a=\frac{(\frac{2\pi r}{T})^2}{r} \\ a=\frac{4\pi^2r^2}{T^2r} \\ a=\frac{4\pi^2r}{T^2} \end{gathered}[/tex]Thus, the time period in terms of the centripetal acceleration and radius is,
[tex]T^2=\frac{4\pi^2r}{a}[/tex]Substituting the known values,
[tex]\begin{gathered} T^2=\frac{4\pi^2\times1.5}{2.5} \\ T^2=23.69 \\ T\approx4.9\text{ s} \end{gathered}[/tex]Hence, the time period to complete one revolution is 4.9 seconds.