If (theta) is equal to (alpha) at the time the box is just about to slide down the plank, the coefficient of static friction between the plank and box is
-
A.
sin(alpha) -
B.
cos(alpha) -
C.
tan(alpha) -
D.
sec(alpha) -
E.
cot(alpha)
Correct Answer: Option C
Explanation
(mu = frac{F}{R} = frac{W sin theta}{W cos q})
= tan(theta)