Grade 10
  1. Mechanics  1.1. Dynamics  1.1.1. Motion in one dimension  1.1.2. Motion in two dimensions  1.1.3. Displacement and Distance  1.1.4. Speed and Velocity  1.1.5. Acceleration  1.1.6. Graphical representation of motion  1.1.7. Equations of motion  1.1.8. Free fall and acceleration due to gravity  1.1.9. Projectile motion  1.1.10. Relative speed  1.2. Dynamics  1.2.1. Newton's Laws of Motion  1.2.2. Inertia and mass  1.2.3. Force and its types  1.2.4. action and reaction force  1.2.5. Friction and its effects  1.2.6. Coefficient of friction  1.2.7. Circular motion  1.2.8. Centripetal force and centripetal acceleration  1.2.9. Momentum and Impulse  1.2.10. Conservation of momentum  1.2.11. Newton's third law and applications  1.3. Work, Energy and Power  1.3.1. Work done by the force  1.3.2. Work–energy theorem  1.3.3. Kinetic energy  1.3.4. Potential energy  1.3.5. Mechanical energy  1.3.6. Energy Conservation  1.3.7. Power and efficiency  1.3.8. Renewable and non-renewable energy sources  1.4. Gravitational force  1.4.1. Newton's law of universal gravitation  1.4.2. Gravitational field and field strength  1.4.3. Acceleration due to gravity on different planets  1.4.4. Kepler's laws of planetary motion  1.4.5. Orbits and satellites  1.4.6. Weight and apparent weight  1.4.7. Gravitational potential energy
  2. Properties of matter  2.1. States of matter  2.1.1. Solid, liquid and gas  2.1.2. Molecular structure of matter  2.1.3. Intermolecular forces  2.1.4. Plasma and Bose–Einstein condensate  2.2. Pressure  2.2.1. Definition of Pressure  2.2.2. Pressure in liquids  2.2.3. Atmospheric pressure  2.2.4. Pascal's principle  2.2.5. Archimedes' Principle and Buoyancy  2.2.6. Surface tension and capillarity  2.3. Elasticity  2.3.1. Hooke's law  2.3.2. Stress and strain  2.3.3. Elastic Limit and Modulus of Elasticity  2.3.4. Applications of Elasticity
  3. Thermal physics  3.1. heat and temperature  3.1.1. Difference Between Heat and Temperature  3.1.2. Temperature scale  3.1.3. Thermal expansion  3.1.4. Thermal equilibrium  3.2. Heat transfer  3.2.1. Conductivity  3.2.2. Convection  3.2.3. Radiation  3.2.4. Insulation and its applications  3.3. Thermal properties of matter  3.3.1. Specific heat capacity  3.3.2. Latent heat and phase change  3.3.3. Boiling and Melting Point  3.3.4. Heat engines and refrigeration  3.4. Laws of Thermodynamics  3.4.1. Zeroth law of thermodynamics  3.4.2. First law of thermodynamics  3.4.3. Second law of thermodynamics  3.4.4. Carnot cycle
  4. Waves and optics  4.1. Nature and properties of waves  4.1.1. Types of waves in nature and properties of waves  4.1.2. Transverse and longitudinal waves  4.1.3. Wave parameters  4.1.4. Reflection and refraction of waves  4.1.5. Superposition and Interference  4.1.6. Standing Waves and Resonance  4.1.7. Doppler effect  4.2. Sound waves  4.2.1. Characteristics of sound waves  4.2.2. Speed of sound in different mediums  4.2.3. Applications of sound waves  4.2.4. Ultrasound and its uses  4.3. Light Waves and Optics  4.3.1. Nature of light  4.3.2. Reflection of light  4.3.3. Laws of reflection  4.3.4. Mirrors and Image Formation  4.3.5. Refraction of light  4.3.6. Snell's Law  4.3.7. Lenses and Image Formation  4.3.8. Total internal reflection and critical angle  4.3.9. Optical fibre  4.4. Optical Instruments  4.4.1. Microscope  4.4.2. Telescope  4.4.3. Human eye and vision defects  4.4.4. Camera and its working principle
  5. Electricity and Magnetism  5.1. Electrostatics  5.1.1. Electric charge and its properties  5.1.2. Conductors and Insulators  5.1.3. Coulomb's law  5.1.4. Electric field and field lines  5.1.5. Electric potential and potential difference  5.1.6. Capacitors and Capacitance  5.2. Current Electricity  5.2.1. Electric current and its measurement  5.2.2. Ohm's law  5.2.3. Resistance and resistivity  5.2.4. Series and Parallel Circuits  5.2.5. Electric power and energy  5.2.6. Kirchhoff's Laws  5.3. Magnetism and Electromagnetism  5.3.1. Magnetic field and field lines  5.3.2. Magnetic effects of electric current  5.3.3. Electromagnetic induction  5.3.4. Faraday's laws of electromagnetic induction  5.3.5. Transformers and Applications  5.3.6. AC and DC current
  6. Modern Physics  6.1. Nuclear physics  6.1.1. Structure of the atom  6.1.2. Bohr's atomic model  6.1.3. Electron Energy Levels  6.1.4. X-rays and applications  6.2. Radioactivity  6.2.1. Types of radiation  6.2.2. Half-life and radioactive decay  6.2.3. Nuclear reactions and applications  6.2.4. Fission and Fusion  6.3. Quantum physics  6.3.1. Wave–particle duality  6.3.2. Photoelectric effect  6.3.3. Energy quantization  6.3.4. Heisenberg's uncertainty principle
  7. Electronics and Communication  7.1. Semiconductors  7.1.1. Conductors, Insulators and Semiconductors  7.1.2. Diodes and their applications  7.1.3. Transistors and Logic Gates  7.1.4. LEDs and photodiodes  7.2. Communication Systems  7.2.1. Basics of communication  7.2.2. Analog and digital signals  7.2.3. Wireless and optical fibre communication  7.2.4. Radio Waves and Modulation

Grade 10 → Thermal physics ↓


Heat transfer


In the world of thermal physics, it is very important to understand how heat moves from one place to another. Heat is a type of energy, and it moves in a variety of ways. We call this "heat transfer." Let's explore this fascinating concept.

What is heat?

Before we learn how heat moves, we must understand what heat is. Heat is a form of energy. It's energy that comes from the movement of particles in a substance. Everything in the universe is made up of particles like molecules and atoms, and these particles are always moving. The faster they move, the more heat they produce. Even simple things like rubbing your hands together produce heat because it makes the particles in your skin move faster.

How does heat move?

Heat can travel in three main ways: conduction, convection, and radiation. Each way is different, but they all move energy from one place to another.

Conductivity

Conduction is the transfer of heat through direct contact. Imagine you are touching a metal spoon that is placed in a hot pot of soup. The spoon gets hot because the heat moves from the soup to the spoon. That is conduction.

    P = K * A * (T1 - T2) / D

In the above formula,

  • P is the rate of heat transfer.
  • k is the thermal conductivity of the material.
  • A is the area through which the heat flows.
  • T1 - T2 is the temperature difference between the two ends.
  • d is the thickness of the material.

Materials that conduct heat well, such as metals, are called conductors. Materials that do not conduct heat well are called bad conductors, such as wood or plastic.

Visual example of conduction

Metal Wood

In the picture we see two materials: metal and wood. The arrows show heat flowing through both materials. Notice that heat flows more easily through metal than through wood.

Convection

Convection is the transfer of heat by the movement of fluids or gases. It occurs because warmer areas of the fluid or gas move toward cooler areas. As this happens, the cooler fluid or gas replaces the warmer areas, and a continuous circulation pattern is formed.

A common example of convection is boiling water. When you heat water in a pot, the water at the bottom heats up and rises. Then cooler water sinks down to take its place. This cycle creates a convection current that eventually heats all the water.

Visual example of convection

In a visual example, we can see how a fluid moves around due to convection currents. This is how liquids or gases transfer heat.

Radiation

Radiation is the transfer of heat energy via electromagnetic waves. Unlike conduction and convection, radiation does not need a medium to travel. Heat from the Sun reaches the Earth by radiation. Even in space, where there is a vacuum, solar energy travels via radiation.

When you feel heat from a heater on the other side of the room, even though the surrounding air is not heated, that is radiation. It is heat transferred directly by electromagnetic waves.

Visual example of radiation

In this example, the heat from the orange object travels in a straight path towards the grey circle. This is similar to how the sun's energy reaches us in the form of radiation.

Everyday examples of heat transfer

Understanding how heat works gives us insight into everyday life. Here are some examples of how we see conduction, convection, and radiation:

  • Conduction: Cooking is a great example of this. When a pot is placed on the stove, the heat from the stove first goes into the pot and then into the food.
  • Convection: The human body uses convection to cool itself. When we sweat, the fluid on our skin evaporates, cooling us as air flows over the wet surface.
  • Radiation: Using microwaves to heat food causes radiation. This type of radiation works at a different electromagnetic spectrum level than the sun's heat, using microwave radiation.

Insulation

Insulating materials are essential for controlling the flow of heat. They avoid unwanted heat loss or gain. Think of a thermos flask that keeps your drinks hot or cold. It uses insulating materials to keep the inside temperature constant by reducing heat transfer.

Visual example of insulation

Insulated Box

In this example, heat is trapped inside the insulated box by reducing heat transfer to the outside environment, keeping the inside warmer.

Conclusion

The transfer of heat plays a vital role in our lives and the world around us. From simple tasks like boiling water to complex systems like heating our homes, understanding how heat moves helps us innovate and improve efficiency in a variety of fields.

We've looked at how heat moves through conduction, convection and radiation. Understanding each type of heat transfer allows us to apply knowledge to real-world applications, ensuring we can conserve energy and use resources effectively.


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Heat transfer

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