Question

If the light rays in the incident ray originate at 20º from the surface...

What is the angle for the incident ray?

a.) 10 degrees

b.) 20 degrees

c.) 40 degrees

d.) 70 degrees

e.) 90 degrees


What is the angle for the reflected ray?

a.) 10 degrees

b.) 20 degrees

c.) 40 degrees

d.) 70 degrees

e.) 90 degrees


Can someone help me with this please? Thank you!

Answer 1

Given :

The light rays in the incident ray originate at 20º from the surface.

To Find :

The angle for the incident ray.

Solution :

We know angle of incidence is measured from perpendicular to the surface .

So,

`\theta_i = 90^o - 20^o\\\\\theta_i = 70^o`

Now, we know by law of reflection :

Angle of reflection = Angle of incident

`\theta_r = 70^o`

Therefore, the angle of incident and reflection is 70° each.