Angle turned by train in 1 minute

Linear displacement
$\begin{align}
s & = vt \\
& = \left( 8 \, \dfrac{\text{mi}}{\text{hr}} \times \dfrac{5280 \text{ ft}}{1 \text{ mi}} \times \dfrac{1 \text{ hr}}{60 \text{ min}} \right) \times (1 \, \text{min}) \\
& = (704 \text{ ft/min}) \times (1 \, \text{min}) \\
& = 704 \text{ ft}
\end{align}$
 

Angular displacement
$s = r \theta$

$704 = 2500 \, \theta$

$\theta = 0.2816 \text{ rad}$

$\theta = 0.2816 \text{ rad} \times \dfrac{180^\circ}{\pi \text{ rad}}$

$\theta = 16.13^\circ$   ←   answer