For uniform circular motion, $v$ is constant, so $\stackrel{\.}{v}\=0$. The satellite traverses a circle of radius 4400 miles, with the center at the center of the earth. Hence, $\mathrm{\κ}\=1\/4400$. From

$m g \mathbf{N}\=m {\mathbf{a}}_{\mathbf{N}}\mathbf{ }\mathbf{N}\=m \left(\mathrm{\κ} v^2\right)\mathbf{N}$ 

working in the units determined by $g$, obtain the equation $30\=\frac{v^2}{4400\cdot 5280}$, and hence,

 $v\=26400$ ft/s = $\frac{26400}{5280}\=5$ m/s = $5\cdot 3600\=18000$ m/h