Calculating speed of minute hand on a clock 
The minute hand on a clock is $12 \text{ cm}$ long. Calculate the speed of its free end.

Is the following correct ? I have already worked out its angular speed from the previous question.
$$v = \omega r \\
\omega = 1.75\times 10^{-3} \text{ rad s$^{-1}$} \\
r = 12\text{ cm} = 1200\text{ m}$$
$$\begin{align}\therefore v &= (1.75\times 10^{-3} \text{ rad s$^{-1}$})\times (1200\text{ m}) \\
\therefore v &= 2.1\text{ ms$^{-1}$}\end{align}$$

The tip travels $2\pi\cdot12$ cm in one hour, hence $2\pi\cdot12/3600$ cm/s. (About $0.21$ mm/s.)
