Waves can transfer energy from one place to another. There are two main types of waves - mechanical waves, which require a medium and can only travel through matter, and electromagnetic waves, which can travel through vacuums. The key characteristics of waves include wavelength, frequency, amplitude, crest, and trough. Mechanical waves can be transverse, with oscillations perpendicular to the direction of travel, or longitudinal, with oscillations parallel to travel. Sound waves are an example of longitudinal mechanical waves.
Energy is the ability to do work.
Everything that happens in the world uses energy!
Most of the time we can’t see energy, but it is
everywhere around us!
Energy is the ability to do work.
Everything that happens in the world uses energy!
Most of the time we can’t see energy, but it is
everywhere around us!
Waves (Grade 7, Quarter 3) Suggested Guide for DiscussionRachel Espino
A suggested powerpoint presentation guide for discussion for Gr.7 teachers on the characteristics and categories of waves. It also includes a simple quiz (under knowledge category) as an assessment
“HEAT”
Heat is a form of energy that flows from warmer bodies to colder bodies.
It is viewed as a form of energy that is transferred from one body to another due to a difference in temperature.
The SI unit of heat is joule (J).
Common unit of heat is calorie.
CALORIE the amount of heat needed to change the temperature of one gram of water from the pressure of the atmosphere.
TEMPERATURE
LAYMAN’S TERM
- It is the degree of hotness or coldness of an object.
Molecular level
- A measure of the average kinetic energy of these molecules.
Based from our sensory experiences:
“Can we use our senses to determine temperature?”
THERMOMETER
TYPES OF THERMOMETER
The most common type of the thermometer.
THERMOCOUPLE
-two different metals (usually copper and iron) that are twisted together
INFRARED THERMOGRAMS
-a device (camera) that measures the amount of radiant energy given off by an object
TEMPERATURE SCALES
TEMPERATURE SCALES
Waves (Grade 7, Quarter 3) Suggested Guide for DiscussionRachel Espino
A suggested powerpoint presentation guide for discussion for Gr.7 teachers on the characteristics and categories of waves. It also includes a simple quiz (under knowledge category) as an assessment
“HEAT”
Heat is a form of energy that flows from warmer bodies to colder bodies.
It is viewed as a form of energy that is transferred from one body to another due to a difference in temperature.
The SI unit of heat is joule (J).
Common unit of heat is calorie.
CALORIE the amount of heat needed to change the temperature of one gram of water from the pressure of the atmosphere.
TEMPERATURE
LAYMAN’S TERM
- It is the degree of hotness or coldness of an object.
Molecular level
- A measure of the average kinetic energy of these molecules.
Based from our sensory experiences:
“Can we use our senses to determine temperature?”
THERMOMETER
TYPES OF THERMOMETER
The most common type of the thermometer.
THERMOCOUPLE
-two different metals (usually copper and iron) that are twisted together
INFRARED THERMOGRAMS
-a device (camera) that measures the amount of radiant energy given off by an object
TEMPERATURE SCALES
TEMPERATURE SCALES
Twitter, Tweeting, and Togetherness: The Impact of Social Media on Freshman ...Biola University
This study examines how Twitter is used to build connection among incoming freshman college students to their campus and community. The use of Twitter is examined in light of the theory of Bandura’s social learning theory, Tinto’s three stages, and Astin’s Involvement Theory. This pilot study examines a group of 36 incoming freshmen students who have never used Twitter or have a Twitter account but do not regularly tweet. The study seeks to examine how social media can be used to increase students’ connection to the campus community and leveraged as a medium of peer learning.
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
2. Waves are a Form of Energy
• What do we know about energy?
– It is the ability to do work (make changes)
– It cannot be created or destroyed
– It can be transferred between objects
• Waves are vibrations that transfer energy
from place to place
– back-and-forth movements
• push-and-pull forces
• "disturbance" or oscillation
– spread in all directions
Powerpoint Templates
3. Mechanical vs. Electromagnetic
• Mechanical Waves
– travel ONLY through matter
• energy is transferred from place to place
• matter moves but returns to original location
– travel through a solid, liquid or gas medium
• type of medium affects how quickly the wave can travel
– cannot travel through space where there is no matter
– Examples:
• sound waves
• ocean waves
• seismic waves
Powerpoint Templates
4. Mechanical vs. Electromagnetic
• Electromagnetic Waves
– CAN travel through a vacuum (lack of matter, even air molecules)
– can also travel through matter (solid/liquid/gas)
• Electromagnetic Spectrum
– radio waves, microwaves, infrared waves
– X rays, light, heat
• we'll look at these
in a couple weeks
Powerpoint Templates
5. Anatomy of a Wave
• Crest: highest point
on a wave
• Trough: lowest point Amplitude
on a wave Node
• Node: midway point
between crest & trough
• Wavelength: distance between crests (λ in meters)
• Amplitude: height of the wave (A) - (MIDDLE to crest)
– shows how much energy a wave carries
• Frequency: how many waves hit a certain point every
second (Hz = Hertz = waves per second)
Powerpoint Templates
6. Transverse Waves
• A transverse wave has vibrations (oscillations)
perpendicular to the direction the wave travels
– propagation (direction wave travels) is to the right
– oscillation is up and down
• May be mechanical or electromagnetic
– Examples: ocean waves, X-rays or light
If the graph show
here represented
1 second of time,
what would the
Oscillation
frequency be?
Answer: 2.5 Hz
Powerpoint Templates
7. Longitudinal Waves
• A longitudinal wave oscillates parallel to the
direction the wave travels
– propagation is to the right
– oscillation is left and right
• All longitudinal waves are mechanical
– Examples: sound waves, seismic waves
• Also called compressional waves
If the graph show
here represented
1 second of time,
what would the
frequency be?
Answer: 3 Hz
Powerpoint Templates Oscillation
8. Longitudinal Waves
• In longitudinal waves, matter is compressed (squeezed
or pushed together) to form the wave motion.
– point of greatest compression = "crest"
– point coils are most spread out (rarefaction) = "trough"
• Amplitude is displayed in how tightly the medium is
squeezed together in its regions of compression.
– more tightly compressed coils Templatesamplitude (more energy)
Powerpoint = higher
9. Sound Waves
• When you hear a sound, it is caused by air
molecules being compressed in waves.
Powerpoint Templates
12. Wavelength & Frequency
• Wavelength, frequency and wave speed can be
described mathematically by the following
equation:
wave speed (v) = frequency (f) x wavelength (λ)
f = v
λ
Powerpoint Templates
13. A, f & λ Relationships
• Beads on a String Demo
f= v
λ
• As frequency increases, the wavelength decreases.
– f and λ are inversely proportional
Powerpoint Templates
14. Practice Problem
• A marine weather station detects waves which are 9.28 meters
apart and 1.65 meters high and travel a distance of 50 meters in
21.8 seconds. Determine the speed, amplitude and frequency of
these waves.
Speed
Speed (v) = distance/time = 50m ÷ 21.8s = 2.3m/s
Amplitude
Amplitude (A) = ½ wave height = .5 x 1.65m = .825m
Frequency
Frequency (f) = v/λ = 2.3m/s ÷ 9.28m = .25 Hz
Powerpoint Templates
15. Frequency & Period
• The period (T) of a wave is the time it
takes for one wave to pass a certain point
(or the time between each wave).
• If this graph shows 1 Period (T)
second of time, the
frequency (f) is 3Hz.
• 3 waves per second
means the period (time
between each wave) is T=1
1/3 of a second. f
Powerpoint Templates
16. Practice Problem
• Strong winds can apply a significant enough force to tall
skyscrapers to set them into a back-and-forth motion. The
amplitudes of these motions are greater at the higher floors and
barely observable for the lower floors. It is said that one can even
observe the swaying motion of the Sears Tower in Chicago on a
windy day.
– As the Sears Tower vibrates back and forth, it makes about 8.6
vibrations in 60 seconds. Determine the frequency and the
period of vibration of the Sears Tower.
f = waves per second = ?/s
T=1
f
f = 8.6/60s = .143 = .14 Hz
period = 1/f = 1 = 6.98s (about 7 seconds)
.14
Powerpoint Templates
Editor's Notes
vacuum = lack of matter (even air molecules)
Suppose you were wading in the ocean at a beach. The amplitude of the waves would basically tell you how high the waves are. People riding surfboards would be happy if the waves had a large amplitude, because that would mean that the waves were high. People wanting a leisurely swim in the ocean would be more happy with small amplitude waves. The wavelength indicates how far apart the wave crests are. Frequency, on the other hand, indicates how many waves will hit you each second if you simply stand there and do not move. It should make sense to you that frequency and wavelength are related in some way. After all, if the wave crests are far apart, not very many of them will hit you in a second. If the wave crests are close together, then several of them can hit you each second. Thus, when wavelength is large, frequency is small, and when wavelength is small, frequency is large. In other words, wavelength and frequency are inversely proportional to one another. When one gets large, the other becomes small.
right angle = perpendicular = 90 degree angle If the graph show here represented 1 second of time, what would the frequency (waves per second) be? Answer: 2.5 Hz
A.K.A. compressional wave
A.K.A. compressional wave
Period - 1/T, so what is the period? 4 seconds (between waves)
if 100 = 1 second, the frequency would be 3Hz. 3 waves per second means the period (time between each wave) is 1/3 of a second