Why does a pencil look bent in water?

This is due to refraction - light from the part of the pencil under water bends as it leaves the water into air, making the pencil appear bent or displaced at the surface.

Does the speed of light change in reflection?

No. In reflection light stays in the same medium so its speed is unchanged. In refraction light enters a new medium and its speed changes, which causes the bending.

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Difference Between Reflection and Refraction

When light meets a surface it can bounce back (reflection) or pass through and bend (refraction).

In short

Reflection is the bouncing back of light from a surface into the same medium; refraction is the bending of light as it passes from one transparent medium into another due to a change in speed.

Reflection vs Refraction - Comparison Table

Basis	Reflection	Refraction
What happens	Light bounces back	Light bends and passes through
Medium	Stays in same medium	Enters a new medium
Cause	Surface blocks light	Change in speed of light
Speed of light	Unchanged	Changes
Governing law	Laws of reflection (i = r)	Snell’s law (n₁sin i = n₂sin r)
Example	Image in a mirror	Straw bent in a glass of water

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Frequently Asked Questions - Reflection vs Refraction

Why does a pencil look bent in water?: This is due to refraction - light from the part of the pencil under water bends as it leaves the water into air, making the pencil appear bent or displaced at the surface.
Does the speed of light change in reflection?: No. In reflection light stays in the same medium so its speed is unchanged. In refraction light enters a new medium and its speed changes, which causes the bending.

Difference Between Reflection and Refraction

Reflection vs Refraction - Comparison Table

Frequently Asked Questions - Reflection vs Refraction

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