Final answer:
An object in water would seem closer to the surface than it really is if light traveled faster in water compared to air because of the refraction of light rays bending away from the normal when transitioning from water to air.
Step-by-step explanation:
The phenomenon that causes an object in water to appear shallower than it actually is, is known as refraction. When light passes from one medium to another, it changes speed, and this change in speed causes the light to bend. In the real world, light travels more slowly in water than in air, but if we suppose the speed of light was greater in water, then the light rays coming from an object underwater would bend away from the normal when they exit the water and enter the air. This bending would result in the light reaching the observer's eyes as if the light came from a position more shallow than where the object is actually located. Therefore, an object underwater would seem closer to the surface than it really is due to the refractive bending of light rays. Since light in reality slows down when it enters water from the air, this explanation would only be hypothetical if the scenario were reversed. A simple ray diagram could demonstrate this principle by showing rays diverging as they exit the water, making the object seem closer to the observer than it is. In actuality, however, the diagram would show rays converging towards the normal line, resulting in the object appearing to be at a shallower depth.