Light Waves

Light Waves

by Lesley Patterson

Light Waves

Light waves are special waves called transverse waves. They still move energy but this time, it's light energy and NOT through a medium. Light waves can travel through space. They are called electromagnetic waves.

Multiple Choice

How are electromagnetic waves different from other waves? 

• They have very short wavelengths 
• They transmit energy instead of matter 
• They can travel through empty space
• They can change direction by reflection 

​Speed of light

​The speed of light is much faster than the speed of sound. That's why you see the lightning before you hear the thunder...

Multiple Choice

Why do you see lightning before you hear the thunder?

• The speed of sound is faster than the speed of light.

• The speed of light is faster than the speed of sound.

• That's just the was it happens.

• Lightning is created before the thunder.

Amplitude is still the height of the wave. The higher the amplitude, the brighter the light.

​

​Frequency is still the number of waves that passes through a point in a given time. Frequency determines the COLOR of the light

​Properties of light waves

Multiple Choice

A light with a high amplitude will be _________than a light with a lower amplitude.

• darker

• dimmer

• brighter

• different colored

Wavelength and frequency

​As the wavelength gets longer, the frequency gets less and less. Lower frequency and longer wavelength means less energy.

​Radio waves have less energy and a longer wavelength than gamma rays.

Multiple Choice

Frequency determines the _________ of visible light.

• color

• brightness

• volume

• pitch

Multiple Choice

Which of the following is true about waves?

• When wavelength increases frequency increases
• When wavelength decreases, frequency increases
• When wavelength decreases, frequency decreases

Multiple Choice

Which wave has the greatest amplitude?

• The blue wave
• The red wave

Multiple Choice

Which wave has a greater frequency?

• A
• B

​EMS has two parts...

​The electromagnetic spectrum has 2 parts:

​1.visible spectrum- these are the colors of the rainbow we can see

​2. invisible spectrum- these are the parts of the spectrum we can't see

• ​microwaves

• ​radio waves

• ​infrared waves

• ​gamma waves

• ​ultraviolet

• ​x-rays

Multiple Choice

Which section of the spectrum is the ONLY one we can see?

• X-rays
• Visible Light
• Gamma Rays
• Ultraviolet Rays

Invisible Spectrum

​Radio Waves have the longest wavelength and the lowest frequency. Radio waves are used in communication.

​Microwaves are also used in wireless networks.

​Infrared have shorter wavelengths than visible light. They can't be seen but can be FELT in the form of heat

​Invisible Spectrum

​Ultraviolet rays have a shorter wavelength and higher frequency than visible light. This is the radiation associated with sunlight. Too much UV light can be dangerous. It can cause sunburns and even skin cancer.

​Invisible Spectrum

​As the wavelength gets shorter, the frequency gets bigger. X-rays have very short wavelengths. X-rays travel through skin and fat and muscle but stop at bones. X-rays can be used to see broken bones.

​Invisible Spectrum

​The wave with the shortest wavelength and the highest frequency is the gamma ray. This form of energy is commonly found in space. Gamma rays can pass through the human body that can damage DNA.

Multiple Choice

The electromagnetic spectrum includes the complete range of electromagnetic waves placed in order of:

• increasing amplitutde
• increasing wavelength
• increasing frequency

​Visible Spectrum

• ​Humans can only see a very small range of waves.

• ​The color depends on the wavelength of the energy.

• ​Red has the longest wavelength of the visible spectrum. Violet has the shortest.

Multiple Choice

Select the correct order of waves on the EMS from the longest wavelength to the shortest wavelength

• Radio, Micro, Infra, Visible, Ultra, X-ray, Gamma
• Gamma, X-ray, Ultra, Vis, Infra, Micro, Radio
• Vis, Micro, Infra, Ultra, X-ray, Gamma, Radio
• Micro, Radio, Vis, Infra, Ultra, X-ray, Gamma

Multiple Choice

Can travel through matter (gas, liquid, solid) and empty space. 

• sound
• light

Multiple Choice

The light we can see. 

• visible
• gamma
• ultraviolet

Multiple Choice

Which electromagnetic waves allow us to diagnose & treat cancer?

• Gamma rays
• X-rays
• Ultraviolet rays

Multiple Choice

Which of the following has wavelengths longer than microwaves?

• Infrared waves
• Radio waves
• Visible light

Multiple Choice

These waves are used to send signals, including WiFi and text messages.

• Gamma
• Microwaves
• Radio
• Ultraviolet

Multiple Choice

These waves make water molecules vibrate and warm up.

• Gamma
• Microwaves
• Radio
• Ultraviolet

Multiple Choice

Which has the SHORTEST wavelength and, therefore, the highest frequency/most energy

• Radio waves
• Ultraviolet Rays
• Gamma Rays
• X-rays

Multiple Choice

Which has the LONGEST wavelength and, therefore, the lowest frequency/energy

• Gamma Rays
• Radio Waves
• Visible Light
• Infrared rays

Multiple Choice

Which of the following is NOT true?

• Radio waves have lowest frequency
• Ultraviolet waves have highest energy
• Gamma waves have highest frequency
• Radio waves have longest wavelengths

Multiple Choice

Which type of electromagnetic radiation is the reason we need sunglasses and sunscreen to avoid getting a sunburn?

• X-rays
• Gamma Rays
• Ultraviolet waves
• Infrared waves

Multiple Choice

Which type of electromagnetic radiation produces the heat we can feel coming from the toaster?

• Radio waves
• Infrared waves
• X-rays
• Gamma rays

Multiple Choice

Makes you get sunburn. 

• x-ray
• visible
• ultraviolet