Two friends each have a rock. If one person throws the rock horizontally as hard as they can and the other person just drops the rock at the exact same time and height, which rock lands first? Explain fully using words and/or diagrams.
They both land at the same time
Both balls start with nil velocity in the vertical direction. They both have the same height to fall and both accelerate in the vertical direction at g, 9.81m/s/s. Hence they both spend the same time falling. The vertical velocity is unaffected by the horizontal velocity.