The Total Force Needed to Drag a Box at Constant $\theta$

Multiple Choice

The total force needed to drag a box at constant speed across a surface with coefficient of kinetic friction $\theta$ _k is least when the force is applied at an angle $\theta$ such that

A) sin $\theta$ = $\mu$ _k.
B) cos $\theta$ = $\mu$ _k.
C) tan $\theta$ = $\mu$ _k.
D) cot $\theta$ = $\mu$ _k.
E) sec $\theta$ = $\mu$ _k.