Reflection EOY notes

Question 1

How are paths of light represented?

Answer 1

In physics, we use

straight lines to represent paths of light;

arrows on the straight lines to represent the
direction in which the light travels.

Question 2

What is the first law of reflection?

Answer 2

The incident ray, reflected ray and the normal at the point of incidence all lie in the same plane.

Question 3

What is the second law of reflection?

Answer 3

The angle of incidence i is equal to the angle of reflection r.

Question 4

What are the types of reflection?

Answer 4

All surfaces reflect light. However, the type of surface will affect how light is reflected off it.
On smooth surfaces, reflection is regular.
On irregular surfaces, reflection is diffused.

Question 5

What are the characteristics of a plane mirror image?

Answer 5

Characteristics of a plane mirror image:
It is laterally inverted.
It is the same size as the object.
It is upright.
It is virtual (it cannot be formed on a screen).
Its distance from the mirror is equal to the distance of the object from the mirror.

Question 6

What are some of the applications of mirrors?

Answer 6

Vision testing
Mirrors are used to make the letters and numbers appear farther than they are.

Instrument scales
Mirrors are placed below the pointer to help users avoid parallax errors.

Periscopes
Two mirrors inclined at 45° can be used to make a periscope.