In the figure below when is the work done by the weight posi

In the figure below, when is the work done by the weight positive? Moving from y_1 to y_2 It cannot be determined. Never. Moving from y_2 to y_1 None of the above.

Solution

When the weight is moving from y2 to y1, then work is done by the weight i.e. positive. Because it is loosing potential energy (y2>y1) which can be converted into useful work. So, option D is the answer.