√ Heat Transfer by Radiation (Radiation), Formulas & Example Problems
Heat Transfer By Radiation (Radiation), Formulas & Example Problems – In this discussion we will explain about heat transfer. Which includes the definition of heat transfer by radiation or radiation, heat transfer formulas and examples of heat transfer problems in a complete and easy to understand way. For more details, please see the review below carefully.
Heat Transfer By Radiation (Radiation), Formulas & Example Problems
Let's discuss the definition of heat transfer first carefully.
Definition of Heat Transfer
The distance between the earth to the sun is 149,600,0000 km and between the earth and the sun there is a vacuum. Making it impossible to transfer heat (heat) by convection or by conduction.
However, we can feel the heat from the sun, which is hundreds of millions of kilometers from the surface of the earth. In this event heat cannot move by conduction. Which in the process of heat transfer by conduction requires that there is an intermediary in the form of a solid substance.
In addition, the heat generated by the sun cannot be transferred by either convection or heat natural convection or forced convection, because there must be a liquid or gas to transfer heat sun. Then how can the sun's heat reach the earth's surface? So, follow the explanation below!
Heat transfer from the sun to the earth's surface can occur by means of radiation (radiation), in which heat does not require a medium to reach the earth's surface. So radiation is heat transfer without an intermediary substance and is in the form of electromagnetic waves. The tool used to detect the presence of radiation (radiation) of heat is called a thermoscope. To make a simple thermoscope is easy. Here is a picture of a simple thermoscope.
Using two used incandescent lamps (lamp A and lamp B) the filament was removed by making a hole in the bottom. Bulb B is blacked out, while bulb A remains. Then the two lamps are connected to a U-pipe containing colored alcohol.
If the heat emission falls on the surface of ball B, the gas pressure inside ball B will increase and the alcohol surface under ball A will rise. If A and B are simultaneously given a heat emission, the alcohol surface under B will still fall and the alcohol surface under A will rise.
The above events illustrate that a black bulb can absorb more heat than a non-blackened bulb. So, it can be concluded that an object with a dull black surface emits or absorbs heat better than an object with a shiny white surface.
Heat Transfer Formula
The rate of transfer of thermal heat emitted by means of radiation by an object was empirically discovered by Josef Stefan in 1879. Stefan suggested that the rate of transfer of thermal heat emitted by radiation by an object is proportional to the surface area of the object and the fourth power of its absolute temperature. The empirical results derived theoretically by Ludwig Boltzmann in 1884 are known as the Stefan-Boltzmann law which can be expressed by the following equation:
P = eσAT44
With description:
P = Power radiated (watts)
e = Emissivity of an object
σ = Stefan's constant (5.6703 x 10-8 W/m2K4).
A = Area of an object that emits radiation (m2)
T = Absolute temperature (K)
The emissivity value of an object depends on the color of the surface of the object. The surface of an object that is perfectly black has a value of e = 1, while for an object that is perfectly white the value is e = 0. So the emissivity value of e in general is 0 < e < 1.
To understand more about heat transfer by radiation (radiation), pay attention and understand the following example questions.
Examples of Heat Transfer Problems
1.A copper sphere has an area of 20 cm2 then heated to incandescent at 127o If the emissivity of the material is 0.4 and the Stefan constant is 5.67 x 10-8 W/m2K4, then calculate the radiation energy emitted by the ball every second.
Completion:
Is known:
A = 20 cm2 = 2 x 10-3 m2
T = (127 + 273) = 400 K
e = 0.4
σ = 5.67 x 10-8 W/m2K4
Asked: P:…?
Answer:
P = eσAT4
P = (0.4).(5.67 x 10-8).(2 x 10-3).(400)4
P = (0.4).(5.67 x 10-8).(2 x 10-3).(256 x 108)
P = 1161.23 x 10-3 W
P = 1.61123 W ≈ 1.2 W
So, the radiant energy emitted by a ball in every second is 1.2 watts.
Thus has been explained about Heat Transfer By Radiation (Radiation), Formulas & Example Problems, hopefully add to your insight and knowledge. Thank you for visiting and don't forget to read other articles.
List of contents
Recommendation:
- Preface: Definition, Structure and Examples Preface: Definition, Structure and Examples - How to write a good Preface ?On this occasion, Around the Knowledge.co.id will discuss what is the Preface and other things about it. Let's see…
- Pre-literate Age: Definition, Age Division, Types… Pre-literate Age: Definition, Age Division, Types of Humans, and Their Legacy - What is meant by The Age of Pre-literacy? On this occasion, Around the Knowledge.co.id will discuss what is the Age of Pre-literacy and other things Which…
- √ Definition of Guttation in Plants, Process & Differences… Definition of Guttation in Plants, Complete Process & Differences - In this discussion we will explain about guttation in plants. Which includes the understanding of guttation in plants, processes, differences in guttation and transpiration…
- √ Definition of Denudation, Factors, Processes and Impacts… Definition of Denudation, Factors, Processes and Impacts (Complete) - In this discussion, Knowledgeable. Com will explain about Denudation. Denudation is related to the science of geology which discusses the process of erosion of the Earth's surface. Understanding…
- Belief in the Last Days: Definition, Proof, Signs of the Last Hour,… Belief in the Last Days: Definition, Propositions, Signs of the Last Days, Events at the End of Days, Their Functions and Lessons - What is the Meaning of Faith in the Last Day and Its Benefits?
- √ Definition of Plant Tissue, Structure, Characteristics, Functions &… Definition of Plant Tissue, Structure, Characteristics, Functions & Types - On this occasion Around Knowledge will discuss Plant Tissues. Which in the discussion this time is one of the materials for…
- √ Definition of the Solar System, Theory Formed and Its Structure… Definition of the Solar System, Formed Theory and Structure (Complete) - In this discussion we will explain about the solar system. Which includes the understanding of the solar system, the theory of the formation of the solar system, and the arrangement of the solar system...
- Islamic Words of Wisdom Islamic Words of Wisdom - On this occasion, SeputihKnowledge.co.id will discuss Islamic Words of Wisdom and examples. Let's look at the discussion together in the article below to get more...
- Short Story Text: Definition, Characteristics, Structure, Elements and Examples Short Story Text: Definition, Characteristics, Structure, Elements and Examples - What is a Short Story Text? Let us…
- Megalithic: Definition, Characteristics, Belief Systems and… Megalithic: Definition, Characteristics, Belief Systems and Legacy - What is meant by Megalithic and when did it occur? On this occasion, Seputarknowledge.co.id will discuss what is Megalithic and other things...
- Types of Energy: Understanding According to Experts, Properties and… Types of Energy: Understanding According to Experts, Properties and Examples of Energy Changes - What are they what kind of energy is there? naturally…
- Examples of Scientific Work: Functions and Rules of Language Examples of Scientific Papers: Functions and Rules of Language - What are examples of good and correct forms of writing scientific papers? Previously, Seputar the knowledge.co.id has discussed Scientific Work: Definition, Characteristics, Benefits,…
- Badminton Game: History, Techniques, Rules, Means… Badminton Game: History, Techniques, Regulations, Facilities and Infrastructure - On this occasion About the knowledge.co.id will discuss the game of badminton and of course about other things as well covered it. Let's see…
- √ 14 Examples of Renewable Natural Resources 14 Examples of Renewable Natural Resources - On this occasion, Around Knowledge explains about Natural Resources. Which in this discussion discusses several types and examples…
- Vector: Definition, Material, Formulas and Example Problems Vector: Definition, Material, Formulas and Example Problems - What is meant by Vector in operation mathematics? On this occasion, Around the Knowledge.co.id will discuss vectors and other matters about it.…
- Air Pressure: Definition, Types, Gauges, Formulas and… Air Pressure: Definition, Types, Gauges, Formulas and Factors Affecting It - What is meant with air pressure?, On this occasion, Se regarding the knowledge.co.id will discuss it and of course other things...
- Types of Color Types: Definition, Characters and Explanations Types of Color Types: Definition, Characters and Explanations - What are the types of colors and their explanations? On this occasion, Seputarknowledge.co.id will discuss it and of course the things that also cover it.…
- Definition of the Solar System and Members of the Solar System (Discussion… Definition of the Solar System and Members of the Solar System (Full Discussion) - Briefly and completely aroundknowledge.com will explain the meaning of the solar system and its members Sun. Here's an explanation. Definition of the Solar System and its Members…
- Computer Hardware: How it Works, Types, Examples and… Computer Hardware: How it Works, Types, Examples and Functions - In today's computerized era, we are definitely familiar with computers and their devices. However, some may not know...
- Chemical Equilibrium: Definition, Laws, Formulas, Example Problems Chemical Equilibrium: Definition, Laws, Formulas, Example Problems - In this discussion we will explain about chemical equilibrium, formula law and equipped with examples of chemical equilibrium with complete and...
- Mangrove Forests Are: Characteristics, Benefits, Causes of Damage And… Mangrove Forests Are: Characteristics, Benefits, Triggers of Damage and Countermeasures - What is meant by forest mangroves and their functions? On this occasion, Se regarding the knowledge.co.id will discuss it and of course about it other…
- √ Definition of Concave Mirror, Special Rays, Shadow Properties,… Definition of Concave Mirror, Special Rays, Properties of Shadows, Formulas, Example Problems - In this discussion we will explain about concave mirrors. Which includes the notion of a concave mirror, the special rays of a concave mirror, the formula...
- Examples of Journals: Definition, Functions and Types of Journals… Journal Example: Definition, Functions and Types of Accounting Journal - What is meant by a Journal in the world of accounting? At this time, Around the Knowledge.co.id will discuss Journals in the world of accounting and things…
- Environmental Speech: Definition, Purpose, Characteristics and… Environmental Speech: Definition, Purpose, Characteristics and Examples - How is the text of environmental speech structured? what's good and right?, On this occasion, Seputarknowledge.co.id will discuss it and of course things Which…
- Mileage Formula: Definition, Average Average Speed,… Mileage Formula: Definition, Average Speed, Time Measurement and Example Problems - How to Measure distance use the? formula. On this occasion, Seputarknowledge.co.id will discuss it, including measuring time And…
- Conductors Are: Characteristics, Functions, Terms and… Conductors Are: Characteristics, Functions, Terms and Examples - What is a Conductor?, On On this occasion, Seputarknowledge.co.id will discuss it, including functions and of course other things as well covered it. Let us…
- √ The Definition of Earth's Rotation and Its Consequences (Discuss… Definition of Earth's Rotation and the Consequences of Its Occurrence (Full Discussion) - In this discussion, we will explain the Earth's rotation. Which includes the understanding of the earth's rotation and the consequences of its occurrence with a complete discussion and...
- 31 Benefits of Tomatoes for Skin Health & Beauty 31 Benefits of Tomatoes for Health & Facial Skin Beauty - Tomatoes are one of the plants found in South America, tomatoes are in the family of green or red peppers, potatoes. Amongst the community…
- Air is: Definition, Benefits, Types & How to Take Care of It Air is: Definition, Benefits, Types & How to Take Care of It - In this discussion about knowledge.co.id will explain about Air. Which includes the meaning, benefits, types and how to maintain with a complete discussion...
- Where Does Solar Energy Come From?: Geographic Layers… Where Does the Sun's Energy Come From?: Geographic Layers of the Sun and Thermonuclear Fusion Reactions - How Does the Sun Produce Energy? On this occasion, Around the Knowledge.co.id will discuss it and of course things which also…