Vocabulary Energy Wave Amplitude Conduction Convection Radiation Color spectrum Wavelength Potential...
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Waves & Energy
Vocabulary Energy Wave Amplitude Conduction Convection Radiation Color spectrum Wavelength Potential energy Kinetic energy Light energy Chemical energy
Vocabulary Energy Wave Amplitude Conduction Convection
Radiation Color spectrum Wavelength Potential energy Kinetic energy
Light energy Chemical energy Mechanical energy
Slide 3
What is Energy? Energy is defined as the ability to do work
Work is using energy to move something
Slide 4
What are Waves? A wave is a disturbance that transfers energy
from place to place. Most waves need a medium or substance to
travel through Glass, liquids & solids can all be mediums
Moving objects have energy. A moving object can transfer energy to
a medium, producing waves.
Slide 5
Mechanical Waves Waves that REQUIRE a medium through which to
travel are called mechanical waves. Mechanical waves do not carry
the medium they travel through with them Waves on the ocean do not
move the water molecules with them Molecules stay in place, just
bob up and down transferring the energy onward Mechanical waves are
produced when an energy source causes a medium to vibrate
Slide 6
Types of Waves Mechanical waves are classified by how they move
through a medium. Two types of Mechanical Waves Transverse waves
Longitudinal waves
Slide 7
Transverse Waves Transverse waves move the medium at a right
angle to the direction of the wave Moving a rope up and down,
crests & troughs
Slide 8
Longitudinal Waves Longitudinal waves move the medium parallel
to the direction in which the waves travel Like a slinky being
pushed back and forth Compressions: when the coils or waves are
close together Rarefactions: when the coils or waves are farther
apart. Example: Sound
Slide 9
Properties of Waves Foldable Fold your paper into 4 sections
Label sections speed, amplitude, frequency, and wavelength In each
section write: Definition How you measure it in longitudinal and
transverse waves 3 facts On the back, draw and label an example of
each wave
Slide 10
Waves Wavelength Amplitude Frequency Speed The energy of a wave
depends on the wavelength
Slide 11
Wavelength A wave travels a certain distance before it starts
to repeat its motion The distance between two corresponding parts
of a wave Crest to crest Trough to trough
Slide 12
Amplitude Amplitude is the rise of a wave from the rest
position The more energy a wave has, the greater the amplitude. It
takes more energy to make a higher or greater amplitude. Rest
position
Slide 13
Amplitude Amplitude of transverse waves: the maximum distance a
wave moves up or down Amplitude of longitudinal waves: measurement
of how compressed or rarefied the waves are. Dense compressions
means it has a large amplitude
Slide 14
Frequency Number of complete waves that pass a given point in a
certain amount of time. If one wave passes by every second, the
frequency is 1 wave per second. Frequency is measured in hertz (Hz)
1 Hz
Slide 15
Speed Light waves travel faster than sound waves (about a
million times faster!) Speed = how far the wave travels in a given
length of time Speed = distance/time
Slide 16
Related Formulas Speed, wavelength and frequency are related to
one another Speed = Wavelength X frequency Frequency =
Speed/Wavelength Wavelength = Speed/Frequency If you know two of
the variables, you can solve for the other If you increase the
frequency, the wavelength decreases
Slide 17
Practice Complete the practice Wave Math worksheet for
homework!
Slide 18
What are Waves? Waves that do not require a medium to travel
are called electromagnetic waves Light from the sun
Slide 19
Electromagnetic Waves Transverse wave that transfers electrical
and magnetic energy Moves at the speed of light (186,000 miles per
second) Do not require a medium, so they can travel through empty
space, like space (vacuum)
Slide 20
Electromagnetic Spectrum All electromagnetic waves travel at
the same speed, but they have different wavelengths and
frequencies. The electromagnetic spectrum is the complete range of
electromagnetic waves in order of increasing frequency
Slide 21
Electromagnetic Spectrum Made up of: Radio waves-radio, tv,
microwaves Infrared rays-heat lamps, infrared cameras Visible
light-colors, light we see Ultraviolet rays-rays from the sun
X-rays-medicine, engineering Gamma rays-some radioactive
materials
Slide 22
Electromagnetic Project Draw and label the Electromagnetic
Spectrum. Follow the example I show. Use page O74.
Slide 23
Waves Mini-Lab Needed materials: string, water, container,
dropper, Create an example of a transverse wave with string Using
pages O 24, follow the lab instructions. Answer the analysis
questions. On pg 24 do not answer question 6. Write & fill in
the table.
Slide 24
Worksheet Complete the worksheet Properties of Waves You may
use your notes, not your neighbor! Complete the worksheet
Interactions of Waves. Use book pages O 17-23.
Slide 25
Properties of Waves Complete the worksheet Waves & Energy
You may use your book or notes as a reference if necessary.
Slide 26
Waves Reading & Worksheet Read pages O 17-26. Use the
worksheet provided as a guide to your reading Complete the
worksheet Interactions of Waves
Slide 27
Waves Electromagnetic Transverse Waves Do need a ________ to
travel through. Examples of EM waves: (pg O 74) Highest parts
called ____. Lowest parts called ________. _____ waves. Spread-out
parts called ______. Dont need a ________to travel through.
Close-together parts called ___.
Slide 28
Lab Tuning Forks, from the book manual.
Slide 29
ENERGY! List types of energy: Light Sound Earthquake waves Heat
Wind? Electrical Chemical Nuclear Energy is the ability to do work
or cause change When an object is moved because of energy, the
energy is transferred to the object Energy is measured in JOULES
(J)
Slide 30
Energy Three mini-labs to complete with observations 1.Compare
the transfer of energy through various mediums Sound Light Heat
Earthquake waves
Slide 31
Heat Heat is thermal energy moving from a warmer object to a
cooler object. The energy depends on the movement of the atomslots
of movement = higher heat Does temperature rise at the same rate
for everything? Hot sand & cold water. Specific Heat: amount of
heat needed to increase the temperature but the temperature does
not increase at the same rate for everything How is heat
transferred?
Slide 32
Conduction: heat is transferred from one object to another
without the movement of matter. Examples? Convection: heat is
transferred by the movement of currents within a fluid. Examples?
Radiation: transfer of energy by electromagnetic waves
Examples?
Slide 33
Heat Transfer Mini-Lab Compare the transfer of heat by
conduction, convection & radiation. Provide examples of
each
Slide 34
Light Energy, AKA Electromagnetic Can transfer energy without a
medium Transverse wave that transfers electrical and magnetic
energy through vibration Light behaves like waves and packets at
the same time Electromagnetic waves have the same speed in a vacuum
but have different wavelengths and frequencies The amount of energy
carried by an EM wave increases with frequency EM spectrum made up
of radio waves, microwaves, infrared waves, visible light,
Ultraviolet waves, X-rays, Gamma rays. See page O 75
Slide 35
Light Energy Mini-Lab Demonstrate how white light can be
separated into the visible color spectrum. As light passes through
a prism, the waves are bent or refracted Red wavelengths bend the
least Complete five different observations with the prisms. For
each, draw (using the colored pencils) the way you see the light
separated. Use each of the light sources and try at least two
different prisms.
Slide 36
Potential & Kinetic Energy Kinetic Energy: The energy an
object has due to its motion What can effect kinetic energy?
Velocity has a greater impact on effecting the overall K.E. Mass
more mass means more E to make it move K.E. = X Mass X Velocity ^2
Potential Energy: stored energy that results from the position or
shape of an object Gravitational, elastic
Slide 37
Potential & Kinetic Energy Mechanical energy is the
combination of kinetic and potential energy Lets talk PENDULUM:
draw a picture, label potential and kinetic Lets talk bouncing ball
Are these examples cyclic
Slide 38
Conversion of Energy Most forms of energy can be transformed
into another type of energy Mechanical (movement) to electrical,
such as a dam Toaster: Electrical to heat Cell phone: Electrical to
electromagnetic Your body: Chemical to mechanical, Chemical to
thermal
Slide 39
Response to Energy Plant to sunlight? Humans to light, sound,
motion Cockroaches to light intensity Name some devices that help
people sense types of energy: i.e., seismograph