7.2 The Laws of Reflection

Question 1

What is an incident ray? What is the reflected ray?

Answer 1

An incident ray is the ray of light that hits a smooth shiny surface, such as a mirror.

The reflected ray is the ray of light which is reflected off of the smooth shiny surface.

Question 2

What is the normal at the point of incidence?

Answer 2

The normal at the point of incidence is the perpendicular at the point of incidence.

Question 3

What is the angle of incidence? What is the angle of reflection?

Answer 3

The angle of incidence is the angle between the incident ray and the normal. Similarly, the angle of reflection is the angle between the reflected ray and the normal.

Question 4

What is the law of reflection?

Answer 4

The law of reflection states that the angle of reflection is equal to the angle of incidence. the incident ray, reflected ray and the normal at the point of incidence all lie on the same surface.

Question 5

For an image to form, how many rays of light are necessary?

Answer 5

For an image to form, minimum two rays of light are necessary. However, there are an infinite number of light rays during irregular reflection.

Question 6

How do we know if our reflection diagram is accurate?

Answer 6

If our reflection diagram is accurate, the image distance and the object distance should be the same.

Question 7

What is necessary for a reflection diagram of a point object.

Answer 7

1. Minimum 2 rays
2. Geometric accuracy
3. Mirror/smoot surface
4. Source light
5. Point object
6. Observers