When investigating gravity and falling objects what is the most likely source of error

The most likely source of error when investigating gravity and falling objects is air resistance or drag. When objects fall, they experience resistance from the air molecules they encounter, which can slow them down and affect the time it takes for them to fall. This can create discrepancies between the expected and observed results of the experiment. Therefore, it is important to minimize air resistance by performing experiments in a vacuum or using objects with a minimal surface area to reduce the drag forces acting on them.