A rod is mounted so that it can turn about one end. At the start, the angle $\theta$ between the rod and the horizontal is $0^{\circ}$. The rod’s weight produces a moment $M$ about the pivot. The rod is then turned in a vertical plane so that the angle $\theta$ of the rod rises from $0^{\circ}$ to $180^{\circ}$. Which graph represents the way $M$ varies with $\theta$?
Physics 9702 · AS & A Level · Turning effects of forces