Answer: [tex]14.9^{\circ}[/tex]
Step-by-step explanation:
Given
Applied force is 9 lb to hold of 35 lb crate on a hill
Suppose the hill makes an angle of [tex]\theta[/tex] with horizontal
There will be two component of weights i.e. along and perpendicular to the hill
Only the component along the hill pulls the crate backwards
So,
[tex]\Rightarrow 35\sin \theta=9\\\\\Rightarrow \sin\theta =\dfrac{9}{35}\\\\\Rightarrow \theta =14.89^{\circ}\approx 14.9^{\circ}[/tex]
