An estimate of the Reynolds number of a stream of water open to the air $10m$ downstream from its source when flowing at $2\frac{m}{s}$ is:

Take:

Density of air $=1\mathrm{.}2kg{m}^{-3}$ Density of water $=1000kg{m}^{-3}$ Viscosity of air $=1\mathrm{.}1{10}^{-5}k\frac{g}{m}s$ Viscosity of water $=95{10}^{-5}k\frac{g}{m}s$

$21000000$

$218000$

$25300$

$1820000000$