Change in velocity \(\left| {\overrightarrow {\Delta v} } \right| = 2v\sin (\theta /2)\)
\( = 2(r\omega )\sin (90^\circ /2)\)\( = 2 \times 1 \times \frac{{2\pi }}{T} \times \frac{1}{{\sqrt 2 }}\)
\( = \frac{{4\pi }}{{60\sqrt 2 }} = \frac{{\pi \sqrt 2 }}{{30}}\frac{{cm}}{{\sec }}\) [As \(T = 60 \,sec\)]