Final answer:
Both pennies, when flipped from the same height and assuming no air resistance, will land at the same time because gravity accelerates all objects equally in free-fall.
Step-by-step explanation:
The question asks about the motion of two pennies that are flipped differently and when they will land. According to the laws of physics, specifically gravity, both coins should hit the floor at the same time assuming they are flipped from the same height and there is negligible air resistance. The vertical descent of both coins is only affected by gravity, which imparts the same acceleration on both coins. Whether a coin is flicked horizontally or simply nudged off the table does not affect the time it takes to fall to the ground because the horizontal motion and vertical motion are independent of each other. This is an illustration of the concept that in the absence of air resistance, all objects in free-fall have the same acceleration regardless of their mass. It is similar to what happens when a coin is dropped inside an airplane; to an observer inside, it appears to fall straight down due to gravity, while an observer outside would see it move horizontally as it falls.