Question

In some applications dealing with very high speeds, the velocity is measured
in mm/

Answer 1

$a) \ 25mm/\mu{s}=\dfrac{25\times{10^{-3}}}{10^{-6}}=25000m/s$

$b)\ \dfrac{25000\times{0.000621}}{\frac{1}{60\times{60}}}=55890mi/h$