Final answer:
The velocity of the water flowing over a flat surface is 4 ft/s (Option c).
Step-by-step explanation:
The velocity of water is a measure of the rate at which it moves. In this case, the given information states that water flows over a flat surface at a velocity of 4 ft/s (Option c).
This velocity is a straightforward measure of speed, representing the distance covered by water in one second. It is important to understand that velocity is a vector quantity, meaning it has both magnitude and direction. In this context, the magnitude is given as 4 ft/s, indicating that the water is moving at a rate of 4 feet per second along the flat surface.
No further calculations or conversions are needed in this scenario. The answer directly corresponds to the provided information, indicating that the velocity of the water is 4 ft/s.