An object with weight W is dragged along a horizontal plane by a force acting along a rope attached to the object. If the rope makes an angle with the plane, then the magnitude of the force is where μ is a constant called the coefficient of friction.
(a) Find the rate of change of F with respect to θ.
(b) When is this rate of change equal to 0?
(c) If W = 50, lb and μ= 0.6 draw the graph of F as a function of θ and use it to locate the value θ of for which dF/dθ = 0. Is the value consistent with your answer to part (b)?