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Light. Light travels in a straight line. It will not bend around corners Nor will it travel through your hand. Objects that do not allow light to travel through are called OPAQUE What are some examples that you can think of??. When light hits an opaque object, a shadow is created.
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Light travels in a straight line. • It will not bend around corners • Nor will it travel through your hand
Objects that do not allow light to travel through are called OPAQUE • What are some examples that you can think of??
There are two parts to a shadow: • 1) Umbra – is the fully shaded region • 2) Penumbra- is the partially shaded region
The penumbra forms from some of the light being blocked and some being passing by the opaque object.
Other Light Terms • Transparent: refers to any material that allows light to pass through. • Examples??
Translucent: refers to any material that allows some light to pass through. • Examples??
Luminous: refers to objects that produce light. • Examples??
Non-luminous: refers to objects that do not produce light, but reflect it. • Examples??
Illuminance • Illuminance is the amount of light arriving at one place per unit area. • Luminous Intensity refers to the light that is given off from the surface of an object (such as a candle or lightbulb). • Also known as the brightness
A person sitting further away from a light source will notice that the light is dimmer. • When a person sits closer to the light source, the light is brighter, or the illuminance is more intense.
Ray Diagrams • Light will always travel in a straight line. • A Ray Diagram is used to represent the direction of the path of light. • Straight lines and arrowheads are used to indicate the direction of light.