Week 14 WAVES Light waves Sound waves Waves

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Week 14

Week 14

WAVES Light waves & Sound waves

WAVES Light waves & Sound waves

Waves are Everywhere! • • Ocean waves Earthquake waves Light waves Sound waves

Waves are Everywhere! • • Ocean waves Earthquake waves Light waves Sound waves

Create a Wave 1. Fold construction paper in half (hotdog fold). Title top half

Create a Wave 1. Fold construction paper in half (hotdog fold). Title top half of paper Transverse Wave. Title bottom half of paper Relationship between Frequency and Wavelength 2. At the top - create a transverse wave with 2 crest and 2 troughs using yarn. Label the following parts of the wave: amplitude, wavelength, rest position, crest and trough. The wave should start from the rest position. 3. At the bottom - create a wave with high frequency followed by low frequency. Label each section of the wave. Then explain how frequency and wavelength are related.

Waves Carry Energy! • Waves carry energy from one place to another. • Waves

Waves Carry Energy! • Waves carry energy from one place to another. • Waves do not carry matter.

WAVE: (Definition) • A simple wave has a repeating pattern with a specific wavelength,

WAVE: (Definition) • A simple wave has a repeating pattern with a specific wavelength, frequency, and amplitude. • Definition: A disturbance that carries energy from one place to another.

PARTS OF A WAVE

PARTS OF A WAVE

CREST AND TROUGH • Crest – the top of a wave. • Trough –

CREST AND TROUGH • Crest – the top of a wave. • Trough – the bottom of a wave.

WAVELENGTH • Definition – a certain distance in which the wave repeats itself. •

WAVELENGTH • Definition – a certain distance in which the wave repeats itself. • The distance from any point on one wave to a corresponding point on the next wave. • Example - the distance from the crest of one water wave to the crest of the next wave.

FREQUENCY • Definition – The number of times the pattern repeats itself in a

FREQUENCY • Definition – The number of times the pattern repeats itself in a given amount of time. • The number of wave vibrations (oscillations) produced in one second. Measured in Hertz. • Example - beats per second.

FREQUENCY • Higher frequency = higher energy waves! • Lower frequency = lower energy

FREQUENCY • Higher frequency = higher energy waves! • Lower frequency = lower energy waves!

FREQUENCY & WAVELENGTH • Frequency and wavelength are related!!! • Low frequency = Long

FREQUENCY & WAVELENGTH • Frequency and wavelength are related!!! • Low frequency = Long wavelength LOW Energy • High frequency = Short wavelength HIGH Energy

AMPLITUDE • The maximum height or depth of a wave. • The total distance

AMPLITUDE • The maximum height or depth of a wave. • The total distance a wave moves (oscillates) from its resting position. • Examples: • Sound waves get LOUDER. • Light waves get BRIGHTER.

AMPLITUDE • High amplitude = Stronger wave (Higher Energy) • Low amplitude = weaker

AMPLITUDE • High amplitude = Stronger wave (Higher Energy) • Low amplitude = weaker wave (Lower Energy):

PART 2: TWO TYPES OF WAVES

PART 2: TWO TYPES OF WAVES

Two Types of Waves 1. Transverse waves (light waves, ocean waves) 2. Longitudinal waves

Two Types of Waves 1. Transverse waves (light waves, ocean waves) 2. Longitudinal waves (sound waves, some earthquake waves)

Transverse Waves • Transverse waves cause particles to move perpendicular to the direction the

Transverse Waves • Transverse waves cause particles to move perpendicular to the direction the wave moves. • The particles move up and down while the wave moves left to right. Wave motion Medium motion Looks Like This!!!!!

Transverse Waves • EXAMPLES: • Light waves • Ocean waves • Stadium waves

Transverse Waves • EXAMPLES: • Light waves • Ocean waves • Stadium waves

Longitudinal (Compression) Waves • Longitudinal (compression) waves cause particles in a medium (such as

Longitudinal (Compression) Waves • Longitudinal (compression) waves cause particles in a medium (such as air) to compress and then rebound. • The particles vibrate in the same direction as the wave moves. (i. e. , parallel to the direction the wave is traveling. ) Wave motion Looks Like This!!!!! Medium motion

Longitudinal Waves • EXAMPLES: • Wave on a slinky • Sound waves • Some

Longitudinal Waves • EXAMPLES: • Wave on a slinky • Sound waves • Some earthquake waves (P waves)

PART 3: LIGHT WAVES (Example of a Transverse Wave)

PART 3: LIGHT WAVES (Example of a Transverse Wave)

LIGHT WAVES • Travel in transverse waves • Light does NOT need a medium

LIGHT WAVES • Travel in transverse waves • Light does NOT need a medium to travel through. (It can even travel in the vacuum of space!) Wave motion Medium motion

LIGHT WAVES • Includes visible light as well as light waves that we cannot

LIGHT WAVES • Includes visible light as well as light waves that we cannot see: radio waves, microwaves, infrared rays, ultraviolet light, x-rays, gamma rays, and cosmic rays! (All of these combined make up the Electromagnetic Radiation Spectrum!)

Light Waves & Frequency • Red light waves have a low frequency • Blue

Light Waves & Frequency • Red light waves have a low frequency • Blue & Violet light waves have a high frequency

Light Waves & Amplitude • Bright lights have a high amplitude • Dim lights

Light Waves & Amplitude • Bright lights have a high amplitude • Dim lights have a low amplitude

PART 4: SOUND WAVES (Example of a Longitudinal Wave)

PART 4: SOUND WAVES (Example of a Longitudinal Wave)

SOUND WAVES • Travel in longitudinal (compression) waves. • Sound is a mechanical wave,

SOUND WAVES • Travel in longitudinal (compression) waves. • Sound is a mechanical wave, so it needs to travel through a medium. (ex. - solid, liquid, or gas) Wave motion Medium motion

Sound Waves & Frequency • High pitch sound waves have a high frequency •

Sound Waves & Frequency • High pitch sound waves have a high frequency • Low pitch sound waves have a low frequency

Sound Waves & Amplitude • Loud sounds have a high amplitude • Quiet sounds

Sound Waves & Amplitude • Loud sounds have a high amplitude • Quiet sounds have a low amplitude

PART 5: ENERGY OF WAVES

PART 5: ENERGY OF WAVES

WAVE ENERGY & AMPLITUDE • Energy of a wave is proportional to the amplitude

WAVE ENERGY & AMPLITUDE • Energy of a wave is proportional to the amplitude of the wave squared. In other words, Energy ∝ Amplitude 2 A wave with an amplitude 2 times bigger will have 4 times the energy. (22 = 4) A wave with an amplitude 3 times bigger will have 9 times the energy. (32 = 9)

WAVE ENERGY & FREQUENCY • Energy of a wave is proportional to the frequency

WAVE ENERGY & FREQUENCY • Energy of a wave is proportional to the frequency of the wave. In other words, Energy ∝ Frequency A wave with a frequency of 20 waves per minute will have twice as much energy as a wave with a frequency of 10 waves per minute. (20 = 2 x 10)