\(\left(1 \times 10^{-18} g c m s^{-1}\right)=\left(9 \times 10^{-28} g\right)(\Delta v)\)
\(\Delta v=\frac{1 \times 10^{-18} g c m s^{-1}}{9 \times 10^{-28} g}\)
\(=0.11 \times 10^{10} \mathrm{cm} s^{-1}\)
\(1.1 \times 10^{9} \mathrm{cm} s^{-1}\)