Heat flows from warmer objects to cooler ones. There are three main ways heat is transferred: conduction, convection, and radiation. Conduction involves the transfer of heat through direct contact of particles in solids and liquids. Convection involves the transfer of heat by the circulation of fluids like gases and liquids. Radiation involves the transfer of heat through electromagnetic waves and does not require a medium. Good conductors easily transfer heat through conduction while insulators do not. Convection currents transfer heat in fluids when warmer parts rise and cooler parts sink. Dark surfaces are good absorbers and emitters of radiation while shiny surfaces reflect heat.
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes
I have expertise in making educational and other PPTs. Email me for more PPTs at a very reasonable price that perfectly fits in your budget.
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Chapter 4 - Heat, Science, Class 7
HEAT
HOT AND COLD
THERMOMETER
CLINICAL THERMOMETER
HOW TO USE CLINICAL THERMOMETER?
WHILE USING CLINICAL THERMOMETER, THE FOLLOWING PRECAUTIONS SHOULD BE TAKEN
LABORATORY THERMOMETER
WHILE USING LABORATORY THERMOMETER, THE FOLLOWING PRECAUTIONS SHOULD BE TAKEN
DIGITAL THERMOMETER
TRANSFER OF HEAT
CONDUCTION
CONDUCTORS
INSULATORS
CONVECTION
RADIATION
SEA BREEZE
LAND BREEZE
CLOTHES IN WINTERS AND SUMMERS
HOW DO WOOLLEN CLOTHS KEEP US WARM?
Every topic of this chapter is well written concisely and visuals will help you in understanding and imagining the practicality of all the topics.
By Shivam Parmar (Entrepreneur & Teacher)
Heat Transfer Applications
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes.
Introduction
Applications
References
conclusion
HEAT
TEMPERATURE
LAND BREEZE
EFFECT OF HEAT
MEASUREMENT OF TEMPERATURE
CLINICAL THERMOMETERS
DIGITAL THERMOMETERS
SEA BREEZE
TRANSFER OF HEAT
CONDUCTION
CONVECTION
CONDUCTORS AND INSULATORS
RADIATION
DARK COLOURED SURFACES AND COLOURED SURFACES
WIND
I have expertise in making educational and other PPTs. Email me for more PPTs at a very reasonable price that perfectly fits in your budget.
Email: parmarshivam105@gmail.com
Chapter 4 - Heat, Science, Class 7
HEAT
HOT AND COLD
THERMOMETER
CLINICAL THERMOMETER
HOW TO USE CLINICAL THERMOMETER?
WHILE USING CLINICAL THERMOMETER, THE FOLLOWING PRECAUTIONS SHOULD BE TAKEN
LABORATORY THERMOMETER
WHILE USING LABORATORY THERMOMETER, THE FOLLOWING PRECAUTIONS SHOULD BE TAKEN
DIGITAL THERMOMETER
TRANSFER OF HEAT
CONDUCTION
CONDUCTORS
INSULATORS
CONVECTION
RADIATION
SEA BREEZE
LAND BREEZE
CLOTHES IN WINTERS AND SUMMERS
HOW DO WOOLLEN CLOTHS KEEP US WARM?
Every topic of this chapter is well written concisely and visuals will help you in understanding and imagining the practicality of all the topics.
By Shivam Parmar (Entrepreneur & Teacher)
Heat Transfer Applications
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes.
Introduction
Applications
References
conclusion
HEAT
TEMPERATURE
LAND BREEZE
EFFECT OF HEAT
MEASUREMENT OF TEMPERATURE
CLINICAL THERMOMETERS
DIGITAL THERMOMETERS
SEA BREEZE
TRANSFER OF HEAT
CONDUCTION
CONVECTION
CONDUCTORS AND INSULATORS
RADIATION
DARK COLOURED SURFACES AND COLOURED SURFACES
WIND
Transmission of heat. Conduction, Convection, Radiation, Applications, Workin...Aq Sa
Heat is the thermal energy that flows from an object at higher temperature to an object at lower temperature.
The transfer of heat energy from one object to the other is called transmission of heat. Heat energy transfers in three ways,
1. Conduction
2. Convection
3. Radiation
Conduction
If one end of a metal rod is heated with a flame,
the other end will also get heated up after a while. The heat energy is transferred from one end of the rod to the other without the actual movement of particles (atoms or molecules) of the rod. Such a mode of transmission of heat is called conduction.
The transfer of heat through matter without the actual movement of particles from their position is called conduction.
Conduction occurs in solids, liquids and gases, but solids usually conduct heat better than liquids or gases.
In solids, the particles are held very close to each other. They vibrate constantly. When we heat one part of a solid, the particles gain heat energy and start vibrating faster. During their vibration they collide nearby particles and also cause them to vibrate fast. In this way, the particles of hot part of a solid transfer heat to those in the colder parts.
Good and Bad Conductors
Different materials conduct heat at different rates. Materials which allow heat to flow through them easily are called good conductors of heat. Solids such as metals are good conductors of heat.
Materials which do not allow heat to flow through them easily are called bad conductors of heat or heat insulators. Solids such as wood, glass, plastic, styrofoam, etc. are bad conductors of heat. All liquids (except mercury which is a liquid metal) and gases are also bad conductors of heat.
Why metals are better conductors than non-metals?
All solids (metals and non-metals) are made of tiny particles called molecules. But, some solids conduct heat better than others. Put a metal and a plastic spoon in hot water. Which one is a good conductor of heat, metal or plastic? When both spoons receive heat energy, the particles (atoms or molecules) at the hot end of each spoon vibrate fast and collide into neighbouring particles. These particles transfer heat energy to next neighboring particles.
Particles in metals are packed more closely together than non-metals. Metals can transmit heat energy more readily than non-metals (wood, plastic, etc.). The presence of free electrons also speeds up the transfer of heat in metals. When the metal spoon gets heated, the free electrons gain kinetic energy and move farther towards the colder parts of the metal spoon. They collide the atoms in the colder parts and transfer heat energy to them. In metals, heat energy is transferred from one place to another both by the vibrations of particles as well as by the movement of free electrons. That is why metals are good conductors of heat than non-metals(insulators).
Conduction in Liquids and Gases
The process of conduction in liquids and gases is very slow as compared to solids.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
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.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
1. THE TRANSFER OF THERMAL ENERGY
Heat is a form of energy which flows as a result of temperature difference. Consider objects A
and B.
Let θ1 to be the temperature of object A and θ2 to be the temperature of object B such that θA is
greater than θB i.e. θA> θB. Then the heat energy therefore flows from object A toward object
B.
There are three ways in which heat energy can be transferred these include conduction,
convection and Radiation.
1. BY CONDUCTION
Conduction is the transfer of heat through matter (solids) from a region of high temperature to
the region of low temperature. The movement if energy from one atom to another without the
movement of the matter itself. The atom is bonded to neighboring atoms, when heat is supplied
to a part of solid matter, the atom is vibrating, and the vibration is passed on to the neighboring
atom through the bonds. This process spreads the heat throughout the solid matter.
THE CONDUCTORS AND INSULATORS OF HEAT
2. All material which allow heat to flow through them easily are called good conductor of heat such
as most of the metal (copper , silver , iron , aluminium , brass ,lead and etc) but the rate of
conduction differ from one another .
When the metal is heated the electrons which move around the lattice structure carry thermal
energy from a region of high temperature to region of low temperature.
Insulator is all material that they don’t conduct heat e.g. glass, plastic, clothes, rubber and wood
THE SIMPLE EXPERIMENT TO INVESTIGATE THE CONDUCTION OF HEAT BY
METAL
SIMPLE EXPERIMENT
Simple experiment to show that water is bad conductor of heat.
Apparatus:
-Test tube
-Water
-Ice
-Wire gauze
-A pair of tongs
-Source of heat
Procedure:
1-Fill the test tube about 2/3 of water
2-Holding a test tube with a pair of tongs, heat it slightly and heat it over a Bunsen burner as
shown below.
OBSERVATION:
The water near the opened end , the test tube boils but the ice at the bottom of test of test tube
does not melt. This shows that water does not conduct heat (hence water is the poor conductor of
heat)
THE FACTOR AFFECTING THE RATE OF CONDUCTION OF HEAT
3. 1. The rate of conduction of heat is inversely proportional to the length of material. The longer
the material, the lower is production of heat. The longer is the material the more the time it takes
to conduct heat and vice verse.
2. The rate of conduction of heat is inversely proportional to the cross sectional area of the
material perpendicular to the heat flow. The larger is the cross section area the faster is the rate
of conduction of heat.
3. The rate of conduction is directly proportional to the difference in temperature between the
two ends of the material. The higher the temperature difference the higher the rate of conduction
of heat and vice versa
4. The rate of conduction depends on the thermal conducting of the material (nature). The
thermal conductivity is the measure of the rate at which a material conducts heat the higher the
thermal conducting of the material, the higher is the rate of conduction of heat vice versa.
HOW TO MINIMIZE THE LOSS OF HEAT BY CONDUCTION
1. In a system where heat needs to be conserved the heat losses by conduction can be
minimized by thermal insulation. Thermal insulation involves the use of poor or bad
conductors of heat – thermal insulation is used in the boilers. Hot water pipes.
2. In a house insulating against heat loss is achieved by using double glazed window,
carpets, curtains etc.
APPLICATION OF CONDUCTION OF HEAT
1. The cooking materials are made up of metal to efficiently transfer heat to the food being
prepared. The vessels have wooden material or plastic handles that stay cold.
2. In elect devices i.e. computers some components are likely to be damaged by high
temperature. To protect such component the heat sinks are attached to the device. The
heat ink is a material with high thermal conducting i.e. copper that can conduct heat
away.
3. Aluminum is used in making motor engines, piston and cylinders because of its low
density and high thermal conduct.
4. Bad conductors are used for insulation purposes, the clothes we wear are insulators hence
poor conductors of heat which insulates us chains loss of heat by conduction e.g. in hot
region people wear light clothes and vice versa.
5. The bottoms cooking ports need periodic clean to remove layers of heat which improve
the flow of heat.
6. The fibre glass is used under roofs of buildings to prevent heat loss in cold areas.
7. Saw dust which is a poor conductor of heat is used for making hot water pipes.
4. 2. BY CONVECTION
This is the transfer of heat in fluids by currents. When the fluid at the bottom is heated is
expands,as it expands the volume increases. The density decreases as as the volume increases .
Therefore the warmer fluid become less dense and thus raises to the top . The cooler fluid at the
top becomes denser and thus it sinks.
This sets up a convectional current .
NB. The convection involves mass movement of the fluid.
HOW TO MINIMIZE HEAT LOSS BY CONVECTION
1. The losses of heat can be minimized by removing any fluid medium within which
convectional current move. This principle is used in making of the vacuum flask.
2. The losses of heat can be minimized filling hair cavity with insulating materials.
APPLICATIONS OF CONVECTION OF HEAT
1. Land breeze and sea breeze
These are a result of expansion of air caused by unequal heating and cooling of adjacent sea and
land surfaces.
During the day time the land is warmer than the sea thus the air over the land surface
becomes less dense and it rises. The space left is occupied by cooler air from above the
sea surface.
5. During the night time the sea is hotter than the land thus the air over the sea becomes less
dense it rises.
2. Domestics hot water supply system.
Hot water moves from the boiler to where it is used under convection current. Inside the boiler
water is heated making it less dense, water rises and flow into the hot water reserve where it is
stored until needed for use main water supply.
3. Air conditioning systems relied on convectional currently to heat of cool a room. When it is
hot, cool air is blown into the room from the air conditioner. This sinks to the bottom of the room
taking place of the less dense warmer air (warmer air rises and is lead out to be cooled the
recirculated).
6. When it is cold, the heated is turned on heating the surrounding air. The heated air rises up and
cold air moves
down to take the place of the rising warm air. This forms convectional current which continue to
circulate until the air in the room is at the desired temperature.
3. RADIATION OF HEAT
Radiation is the transfer of heat between two bodies by means of electromagnetic waves that
arise due to the temperature of a body in the form of infrared radiation. The transfer of heat by
radiation does not require material medium. It takes place in vacuums. All bodies at a
temperature above absolute O0C emit some radiant energy. The heat from the sun reaches the
earth through radiation. The region between the sun and the earth’s atmosphere is a vacuum. The
heat energy from the sun cannot reach the earth by conduction or convection, it reaches by
radiation.
NB: Radiation heat travels with the speed of light and hence can be reflected absorbed or
transmitted.
ABSORBERS, EMITTERS AND REFLECTORS OF RADIANT HEAT
Dark or black surfaces are good absorbers and emitters of radiant heat. A surface that absorbs all
radiant heat energy is called black body. A polished or shiny surface on other hand is good
reflector of radiant energy but a poor emitter.
EXPERIMENT TO INVESTIGATE THE ABSORPTION AND EMISSION OF
RADIANT HEAT
Apparatus
: Two container (shinny and black) surfaces.
: Two thermometers A and B
: Water
: Heat source
Procedure
: Fill the containers with water to about 2/3 full.
: Place the containers close to the heat source
: Insert thermometers A and B into water contained in the shinny and black surface respectively.
7. Observations:
Thermometers B records high temperature than thermometer A because the black surface
absorbs heat faster than the shine surface.
When the heat source is removed, thermometer B record lower temperature than thermometer A
because a good absorber of heat is a good emitter of heat. This means that black surfaces absorb
and radiant heat energy better than shinny surfaces
HOW TO MINIMIZE HEAT LOSSES BY RADIATION
1. The mechanism of thermos flask to hold hot or cold liquid for a long time. It is designs to
minimize the losses of heat by radiation, conduction and convection. It consists of double
walled glass containers with a vacuum between the walls. The inner wall is coated with
silver. It has a stopper made up of cock or other insulating materials and insulated
materials to keep the inner glass container away from touching the outer container.
8. Both conduction and convection are minimized by vacuum between the glass walls insulated
stoppers and the separators. The silvered walls effectively reflect heat thus preventing heat loss
by radiation.