Velocity of uniform circular motion

1. The problem statement, all variables and given/known data

The minute hand of a clock is 4cm long. Find the average velocity of the tip of the minute hand between 11.00 am to 11.30 am. (in m/s)





2. Relevant equations







3. The attempt at a solution



1.In the motion between 11 am to 11.30 am,

[itex]

\theta=180^o=\pi \text{radiaans}\\

radius=4cm\\

time=30 min\\

[/itex]



Am I right till now?



[itex]

\begin{align*}

v&=\frac{R\theta}{t}\\

&=\frac{4\pi}{30}cm/min\\

&=\frac{4\pi}{30*60*100}m/s\\

&=\frac{3.14}{45000}m/s\\

&=\frac{3.14}{4.5}10^{-5}m/s\\

&=0.69*10^{-5}m/s\\

\end{align*}

[/itex]



But in the book it was given ##4.4*10^{-5}m/s##