Final answer:
The appearance of balls rolling uphill in an illusion video is due to visual misinterpretation of the slopes' orientation, which contradicts how gravity actually affects object movement.
Step-by-step explanation:
The video in question likely showcases an optical illusion where the balls appear to roll uphill due to the misleading visual interpretation of the slopes' orientation, as opposed to the physical reality. Often such illusions play tricks on our perception, manipulating visual cues to create a false sense of gravity and slope direction. In reality, the balls would follow the laws dictated by physics, and without any external force, objects will typically roll downhill due to gravity.
In reference to the examples given, the mention of a merry-go-round and sliding balls refers to demonstrations of coriolis effect or non-inertial frame observations, but this does not directly pertain to the illusion of balls rolling uphill. Additionally, if a ball slides or rolls up a frictionless ramp, the scenario that reaches a greater height will depend on energy conservation and the distribution between kinetic and potential energy, which also does not directly relate to the illusion.