Question

what causes the pencil to look broken in this picture? the light changes temperature, causing the pencil to warm up. the light slows down when it enters the water, causing the pencil to look distorted. the light speeds up when it enters the water, causing the pencil to look straight.

Explanation:

When light travels from air (a less - dense medium) to water (a more - dense medium), it slows down. This change in speed causes the light to bend (refraction). Our eyes perceive the light as coming in a straight - line path. So, the part of the pencil in water appears to be at a different position relative to the part in air, making the pencil look broken. The first option about light changing temperature is incorrect as temperature change of light is not relevant here. The third option is wrong because light slows down (not speeds up) when going from air to water.

Answer:

The light slows down when it enters the water, causing the pencil to look distorted.