ANSWER :
The answer is :
[tex]5\times10^{-3}\text{ }\frac{m}{s}[/tex]
EXPLANATION :
Recall that 1 mm is 10^-3 m
From the problem, we have :
[tex]5\frac{\cancel{mm}}{s}\times\frac{10^{-3}\text{ }m}{1\text{ }\cancel{mm}}=5\times10^{-3}\frac{m}{s}[/tex]
