Physics Review Question

Unit: Waves
Year: 1995 Question#: 40
Question: Which diagram best represents the reflection of light from an irregular surface?

(1 )
(2 )
(3 )


What is this question really asking?




Explanation by: Kristina A

[ Return to question menu ]













Answer 1


INCORRECT

The only way the rays can reflect back the same way they came in is if the surface is smooth and the rays arecoming perpendicular to the surface. The rays in the diagrams are NOT coming in perpendicular to the surface nor is the surface smooth. return to top























Answer 2

INCORRECT

It is not possible by hitting an irregular surface that the parallel rays would remain parallel becasue they don't have the same normals. This would produce a reflection and when we look at an irrergular surface like a sheet of paper or the ground, we don't see a reflection. return to top



























Answer 3


CORRECT

When the rays hit the irregular surface they scatter preventing image formation (also called diffuse reflection). The Law of Reflection holds true in this diagram (an only this diagram) because each of the angles of incidence are equal to the angles of reflection. Because the angles of incidence are not the same on the irregular surface, the parallel incoming rays aren't parallel after they hit the surface. return to top


























Answer 4


INCORRECT

It is not possible for the parallel incoming rays, to remain parallel after hitting the irregular surface. The normals are not the same becasue of the irregular surface. This diagram, with the reflected rays still parallel, would produce a reflection, which irregular surfaces can not do. return to top


























What's this question really asking?

How does the law of reflection apply to light striking an irregulaly shaped surface? return to top

[Home]  [Lessons]  [Review]  [Search]  [Links]

This web site is designed and maintained by Science Joy Wagon and may not be reproduced or redistributed without written permission from Science Joy Wagon.
Contact with comments.