Answer
$2191.9 \ lb $
Work Step by Step
The sine of an angle is defined as force over weight.
Thus, $ \sin \theta=\dfrac{force}{weight}=\dfrac{5000}{15000}$
This implies that $ \sin 26^{\circ}=\dfrac{F}{5000}]$
or, $F=5000 \sin 26^{\circ} =2191.9 \ lb $
