#### Answer

$911.7$ ft

#### Work Step by Step

$350\times15=5250$
In $15$ seconds, the airplane flew $5250$ feet.
Let $h$ be the increase in altitude of the airplane in 15 seconds.
$\sin10^{\circ}=\frac{h}{5250}$
$h=5250\times\sin10^{\circ}$
$h\approx911.7$