In which of the following scenarios is work done against gravity?

When determining whether work is done against gravity, it's crucial to consider the movement of an object in relation to the direction of gravitational force. Lifting a box onto a shelf involves moving the box vertically upward against the force of gravity. In this scenario, the work is calculated based on the weight of the box and the height it is lifted. Since gravity acts downward, any upward movement requires the application of force to overcome this gravitational pull, resulting in work being done against gravity.

In contrast, rolling a ball on the ground, pulling a wagon on a flat surface, and running on a treadmill do not involve overcoming gravitational forces in the vertical direction. These activities primarily involve horizontal movement, where the force exerted is not directed against gravity, and thus do not constitute work done against gravity.