Reflection Examples in Physics

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Reflection.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Physics.

Concept Recap

The bouncing of a wave off a surface, returning it back into the original medium.

Like a ball bouncing off a wall—the wave reverses direction at the boundary.

Read the full concept explanation →

How to Use These Examples

  • Read the first worked example with the solution open so the structure is clear.
  • Try the practice problems before revealing each solution.
  • Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: The angle of incidence equals the angle of reflection, measured from the normal.

Common stuck point: Angles are measured from the normal (perpendicular), not from the surface.

Worked Examples

Example 1

easy
A light ray hits a plane mirror at an angle of 35° to the normal. What is the angle of reflection?

Solution

  1. 1
    The given 35° is the angle of incidence because it is measured to the normal.
  2. 2
    By the law of reflection, the angle of incidence equals the angle of reflection.
  3. 3
    \theta_r = \theta_i = 35°

Answer

\theta_r = 35°
The law of reflection states that the angle of incidence equals the angle of reflection, measured from the normal to the surface. This applies to all types of waves.

Example 2

medium
A light ray strikes a mirror. The angle between the incident ray and the reflected ray is 80°. What is the angle of incidence?

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

easy
A ray of light hits a smooth surface at an angle of 0° to the normal (perpendicular). What happens?

Example 2

medium
A concave mirror has a focal length of 15 \text{ cm}. An object is placed 30 \text{ cm} from the mirror. Use the mirror equation \frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i} to find the image distance. Is the image real or virtual?
← Back to Reflection Practice Mode

Background Knowledge

These ideas may be useful before you work through the harder examples.

waves