Waves PowerPoint - Ithaca City School District

```Waves:
The motion that occurs when energy moves through matter
(liquids, solids, and gases)
Lesson 1: Ocean Waves:
The motion in the ocean
Q: What do you think
is the main cause of an ocean wave?
A.
B.
C.
D.
The Moon
Large Whales
The Wind
Pirates
A: (B) The Wind!
Ocean waves are mostly caused by wind.
 Wind is the energy that travels
through the water (matter) making a
wave motion.
 However, waves are not always
caused by wind. Waves can be caused
by any type of energy or force.
 Tsunamis (storms in the ocean in
which huge waves occur) are caused
by earth quake waves and shifting of
the land at the bottom of the ocean.
True or False: Water is not really
traveling when a wave occurs.
A: True! Water basically stays right where
it is when a wave occurs.
The wave movement is actually the energy passing through
the water.
It’s kind of like if you tied a rope to a tree, and then moved your arm up and
down holding the other end of it. The rope wouldn’t go any where; it just
makes a wave motion as the energy from your arm passes through it.
Q: There are two different kinds of waves:
transverse waves and longitudinal waves. What
kind of waves do you think ocean waves are?
A.Transverse
B.Longitudinal
A: (A) Transverse!
Transverse wave motions occur in right angles
and move up and down.
True or False: It’s impossible to
measure a wave.
A: False!
Waves can be measured in many different ways:
 Wave Amplitude: the height from the still water line to the top of the
wave (its crest) or from the still water line to the bottom of the wave
(its trough.)
 Wave Length: the distance from crest to crest or from trough to
trough.
 Wave Frequency: how fast the wave travels through water, or how
many waves pass a given location per second.
True or False: Ripples in any water
are also considered waves.
A. True
B. False
A: (A) True! Ripples are still just energy moving through
water (matter) creating a smaller wave motion.
Waves can occur in any kind
of water:
 Rivers
 Ponds
 Lakes
 Swimming Pools
 Puddles
 Even Your Bathtub!
Let’s Recap:
 Waves are energy traveling through matter.
 Ocean waves get their energy mostly from the wind.
 Energy is traveling through the water, the water itself
is not actually going any where!
 Ocean waves are transverse waves – waves that
occur in the pattern of a right angle and move up and
down.
 Ocean waves can be measured by their amplitude,
wave length, and frequency.
The Motion in the Ocean
Fun Facts About Ocean Waves
 The stronger the wind, the bigger the wave. For this
reason, surfers often watch the weather closely to see
when a hurricane or strong weather is coming so they’ll
have big waves to surf on.
 The biggest wave ever seen was in 1933 in the North
Pacific. It was 112 feet tall – that’s the height of a seven
story building!
 If a surfer hit a wave hard, it isn’t soft like some people
may imagine. It can actually feel like hitting concrete.
Lesson 2: Sound Waves
Q: Do sound waves and ocean waves
have anything in common?
A. No. Other than the fact that they’re
both called waves, they have nothing
else in common.
B. Yes. They’re both forms of energy
moving through matter.
C. Yes. They are actually both made of
water.
A: (B) Yes. They’re both forms of
energy traveling through matter.
 Sound is caused by vibrations.
 A force causes molecules to vibrate. The vibration is the
energy that travels through the matter (usually air) in the
form of a sound wave.
Q: Do you think sound waves are
transverse or longitudinal waves?
A. Transverse
B. Longitudinal
A: (B) Longitudinal!
Longitudinal Waves travel in one direction without moving
up and down in right angles (which is what transverse
waves do.)
True or False: Sound waves only
travel through air.
A. True
B. False
A: False
Sound can travel through all matter
(solids, liquids, and gases).
Sound traveling through matter from fastest to slowest:
1.Solids
2.Liquids
3.Gases
Q: What causes sound waves to make
different noises?
A. The amount of force causing the
vibration
B. The amount of matter the sound
wave is traveling through
C. The type of matter that the
sound wave is traveling through
D. The length of the initial force
E. All of the above
A: (E) All of the above!
Sound waves make different noises based on:
 The amount of force causing the vibration
 The amount of matter the sound wave is traveling
through
 The type of matter that the sound wave is traveling
through
 The length of the initial force
Transmission of Sound
Let’s Recap:
 Just like ocean waves, sound waves are also energy traveling
through matter (vibrations – usually through air.)
 Sound waves are longitudinal waves (They travel in one
direction without moving up in down.)
 Sound waves can travel through all types of matter.
 The force causing the vibration, the length of the force causing
the vibration, the amount of matter the wave is traveling
through, and the type of matter the wave is traveling through
determines the way we hear the sound wave.
Fun Facts About Sound Waves
 Dogs can hear sound at a higher frequency than humans,
allowing them to hear noises that we can’t.
 Sound is used by many animals to detect danger, warning
them of possible attacks before they happen.
 Sound can’t travel through a vacuum (an area empty of
matter).
 The speed of sound is around 767 miles per hour.
 The loud noise you create by cracking a whip occurs because
the tip is moving so fast it breaks the speed of sound!
Lesson 3: Light Waves and Color
(And Other Waves on the Electromagnetic Spectrum)
Q: Do you think that light waves are
transverse or longitudinal?
A. Transverse
B. Longitudinal
A: (A) Transverse! Light waves travel
in an up and down motion.
 Light waves are waves that travel on
the electromagnetic spectrum.
 They are actually two types of waves
travelling perpendicular to each
other: electric waves and magnetic
waves
 The electromagnetic spectrum gets
its energy from the sun and other
energy sources in our universe.
True or False: Microwaves in our kitchens work by
using waves from the electromagnetic spectrum.
A. True
B. False
A: (A) True! There are 7 types of waves
on the electromagnetic spectrum:
1.
2.
3.
4.
5.
6.
7.
Microwaves,
Infrared
Visible light
Ultraviolet
X-rays
Gamma
*Visible light waves in the form of color are the only waves on the
electromagnetic spectrum that we can see with our eyes.
http://www.darvill.clara.net/emag/index.htm
True or False: All colors of visible light
travel at the same wave frequency.
A. True
B. False
Remember that wave frequency is how many waves travel in a given
location per second (in other words, how fast the waves travel!)
A: (B) False! Each color of visible light
travels at a different frequency.
Q: If the sun emits different colors (waves) of
visible, why do you think we only see white or
“yellow” light in the sun?
A. The sun only makes yellow light.
B. The sun is too far away to see all
of the colors it emits.
C. When our eyes see all of the
colors of visible light together, it
looks like white light to us.
D. Rainbows are only seen when
they’re growing out of pots of
gold.
A: (C) When our eyes see all of the colors of visible
light together, it looks like white light to us.
 The reason we see certain objects as being certain colors, is
because some object will absorb some of the colors of visible
light, but not others. The object will then bounce back the
colors that doesn’t absorb towards out eyes.
 Objects that appear white to us, absorb all of the colors of
visible light.
How We See Color
Let’s Recap
 Light travels in two types of transverse waves:
electric and magnetic waves.
 Visible light is a part of the electromagnetic spectrum
which also includes waves we can’t see (microwaves,
radio waves, ultraviolet waves, etc.)
 Different colors travel at different wave frequencies.
Fun Facts About Electromagnetic Waves
 Light waves travel at about 671 million miles per hour.
 Radio waves and microwaves are used for things like wifi internet,
cell phones, microwaves in our kitchens, speeding radar machines,
the radio that we listen to, and so much more.
 X-rays from the EM spectrum are the waves we use to see the
bones inside our bodies.
 There are some animals that can see ultraviolet waves on the EM
spectrum. That means they can see colors that our eyes can’t see!
Butterflies and a shrimp called the mantis shrimp are two examples.
 There are also some animals that see less colors than we can see.
For example, dogs can’t see all of the visible light that we can see!
http://theoatmeal.com/comics/mantis_shrimp
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