Light Waves Lesson

Intro Light Waves

By Stacy King

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​luminous (emitting light)

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illuminated (reflecting light)

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​Light waves

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Multiple Choice

Why is it that we can see the Moon?

• it is luminous

• it is illuminous

• it is in space

• it is close to the Earth

Light function as both a particle and a wave​

• light "particle" photon

  • defies Newtonian Physics

• Wave

  • photons are energy​ packets

    • moving photons=moving energy

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​Duality of Light

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Multiple Choice

The wave-particle duality of light describes light as...

• a wave only
• a particle only
• both a wave and a particle
• neither a wave nor a particle

​Nothing travels faster than light!

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Light travels

​three hundred MILLION meters each second.

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​Light waves

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Multiple Choice

Which of the following electromagnetic waves travels the fastest?

• gamma rays

• radio waves

• ultraviolet waves

• they all travel the same speed

​When unimpeded, light travels along linear paths.

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Light rays are represented as straight paths.

When they are blocked by solid objects, shadows are formed.

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​Light waves

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Multiple Choice

In order to view an object, you must sight along __________ at that object.

• a line

• a circle

• an ellipse

• a triangle

The intensity of light from a source depends on how close you are to it.​

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• ​When you are close to the source, the light is more intense.

• When you are far from the source, the light is less intense.

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​Light Intensity

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Multiple Choice

As one approaches (gets closer) to a light bulb, the brightness of the bulb....

• Increases (brighter)

• Decreases

• Stays the same

• Changes in some unknown way

The intensity of light is a measure of brightness

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​Intensity is defined as power P per unit area A.

Its units are watts per square meter (W/m2).

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​Light Intensity

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Multiple Choice

A student stands 10 feet away from a light bulb. The student walks toward the light bulb to a 5 feet distance. Which is true? Intensity = 1 / d²

• The bulb appears 2x's brighter

• The bulb appears 4x's brighter

• The bulb appears 5x's brighter

• The bulb appears 25x's brighter

Light is composed of many different color​s

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​ It can be dispersed (separated) using a prism

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​White Light

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Multiple Choice

Sunlight is special because it...

• contains all the colors of the rainbow.

• contains most of the colors of the rainbow.

• contains white light and black light.

• contains black light.

not all light is visible

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​Visible spectrum

​light we can see

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Light does not need a medium to travel ​

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​Light

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Multiple Choice

Which portion of the electromagnetic spectrum includes the entire range of light that can be detected by the human eye? 

• ultraviolet light
• visible light
• infrared light
• x-rays

​Electromagnetic wave

Vibration of charged particles (2D transverse waves)

2 dimensional waves

1. magnetic - horizontal component

2. electrical - verticle component

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​ Wave Behavior

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Multiple Choice

What particles make up light?

• Photons
• Neutrons
• Protons

​Light carries energy and information

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Light

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Multiple Choice

Nearly all the information we have about the universe comes in the form of ___

• light
• sound
• electricity
• fossils

Light can change speed and direction when it interacts with matter​

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Light

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​Reflection

​bouncing off of an obstacle

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​ Wave Behavior

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Multiple Choice

When light bounces off an object- If the surface is smooth and shiny, like glass, water or polished metal, the light will reflect at the same angle as it hit the surface.

• reflection

• refraction

• diffusion

​Refraction

Bending due to change in the medium ​

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​ Wave Behavior

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Multiple Select

Light travels in straight lines.  What two ways is capable to get a light beam to change direction (chose 2)

• refraction

• polarization

• reflection

• constructive interference

• destructive interference