Final answer:
The phenomenon is called refraction, where a pole appears to bend when placed in water due to the change in speed and direction of light passing from air to water.
Step-by-step explanation:
The phenomenon described where a pole appears to bend when placed in a pool of water is called refraction. Refraction occurs because light travels at different speeds in different mediums, such as air and water. When light enters the water, it changes direction and causes the pole to appear bent. This bending of light is due to the change in speed and direction of light as it passes from one medium to another.
Learn more about Refraction of light