Light and MatterIntro to Ray Diagrams

SNC2D

Now that we know that every object that we see is due to the light bouncing off of it…our new learning is goal is to understand HOW exactly the light reflects off of different types of objects

Ray DiagramsRay diagrams are drawings that show the

path that light takes after it leaves its source.

Straight lines are used to represent rays of light. Arrows are included at the end of the line to indicate the direction of the light ray

These diagrams are used to explain why we see shadows and reflections

Why Do Certain Things Look Brighter Than Others?

The more light rays that can reach your eye, the brighter the object will seem!

How Does Light Reflect?Transparent Objects – let light pass through

(transmit) freely. They hardly absorb or reflect any light.

Translucent Objects – transmit some light but not enough to see through a material clearly.

Opaque Objects – absorb and reflect light, but they do not transmit

Which Object is Which?

Translucent!

Which Object is Which?

Opaque!

Which Object is Which?

Transparent!

Which Object is Which?

Transparent,

Translucent and

Opaque!

Here’s What It Looks Like…

Shadows

A shadow occurs when an opaque object blocks the direct light from a light source.

A ray diagram illustrates how the size of a shadow depends on the size of the object blocking the light and its distance from the light source

Shadows

Shadows

Umbra – part of shadow in which all light rays from the light source are blocked

Penumbra – area of partial shadow on either side of the umbra usually due to a very large light source compared to a smaller object

Light ReflectionRegular reflection happens when light rays

strike a smooth surface and reflect in the same direction, staying parallel to one another.

Light ReflectionDiffuse reflection occurs when light rays reflect

off a rough or uneven surface, scattering the light in different directions. You do not see an image when this occurs.