Question

If the wind velocity at a height of 9 m is measured as 50 km/h, the velocity at a height of 0.5 m above the ground can be expected to be, in km/h about

• A. 18
• B. 28
• C. 33
• D. 43

Answer 1

The correct option is C 33

$U_h=C{h}^{1/7}$

$\frac{U_9}{U_{0.5}}={\left(\frac{9.0}{0.5}\right)}^{1/7}=1.5112$

$U_{0.5}=\frac{50}{1.5112}=33.086km/h$