Grade 11
  1. Mechanics  1.1. dynamics  1.1.1. Motion in one dimension  1.1.2. Motion in two and three dimensions  1.1.3. Displacement and Distance  1.1.4. Speed and Velocity  1.1.5. Acceleration and deceleration  1.1.6. Graphical analysis of motion  1.1.7. Equations of motion (advanced derivations)  1.1.8. Free fall and terminal velocity  1.1.9. Projectile motion  1.1.10. Relative velocity in one and two dimensions  1.1.11. Motion of a car on an inclined plane  1.2. Dynamics  1.2.1. Newton's laws of motion and their applications  1.2.2. Inertia and Newton's first law  1.2.3. Force and types of force  1.2.4. Static and kinetic friction  1.2.5. Circular motion and centripetal acceleration  1.2.6. Non-uniform circular motion  1.2.7. Banking of roads and curves  1.2.8. Momentum and Impulse  1.2.9. Conservation of momentum in one and two dimensions  1.2.10. Applications of Newton's Third Law  1.3. Work, Energy and Power  1.3.1. Work done by a constant and variable force  1.3.2. Work–energy theorem  1.3.3. Kinetic and potential energy  1.3.4. Gravitational and elastic potential energy  1.3.5. Conservation of mechanical energy  1.3.6. Power and instantaneous power  1.3.7. Efficiency of machines  1.3.8. Work done by conservative and non-conservative forces  1.4. Rotational motion  1.4.1. Torque and angular acceleration  1.4.2. Rotational equilibrium  1.4.3. Moment of inertia and its applications  1.4.4. Angular momentum and its conservation  1.4.5. Kinetic energy of rolling motion and rotation  1.4.6. Parallel and Perpendicular Axis Theorem  1.4.7. Dynamics of rotational motion
  2. Gravitational force  2.1. Universal gravitation  2.1.1. Newton's law of universal gravitation  2.1.2. Gravitational field and potential  2.1.3. Change in acceleration due to gravity  2.1.4. Kepler's laws of planetary motion  2.1.5. Orbital mechanics and satellites  2.1.6. Escape velocity and orbital velocity  2.1.7. Weightlessness and free fall  2.1.8. Gravitational potential energy and energy in orbits  2.1.9. Black holes and gravitational lensing
  3. Properties of matter  3.1. Fluid mechanics  3.1.1. Density and pressure in liquids  3.1.2. Pascal's theory and applications  3.1.3. Archimedes' Principle and Buoyancy  3.1.4. Bernoulli's equation and applications  3.1.5. Continuity equation and the Venturi effect  3.1.6. Surface tension and capillarity  3.1.7. Viscosity and Poiseuille's Law  3.1.8. Reynolds number and turbulence  3.2. Elasticity and deformation  3.2.1. Hooke's law and the stress-strain relation  3.2.2. Elastic modulus and applications  3.2.3. Deformation and yield strength of solids
  4. Thermal physics  4.1. Heat and temperature  4.1.1. Thermometric properties and temperature scale  4.1.2. Thermal expansion of solids, liquids and gases  4.1.3. Heat transfer system  4.1.4. Specific heat capacity and calorimetry  4.1.5. Latent heat and phase change  4.2. Kinetic theory of gases  4.2.1. Molecular model of gases  4.2.2. Kinetic explanation of temperature  4.2.3. Ideal Gas Equation and Deviations  4.2.4. Mean free path and Maxwell–Boltzmann distribution  4.3. Laws of Thermodynamics  4.3.1. Zeroth Law and Thermal Equilibrium  4.3.2. First Law and Internal Energy  4.3.3. The Second Law and Entropy  4.3.4. Carnot cycle and heat engines  4.3.5. Refrigerators and heat pumps
  5. Waves and oscillations  5.1. Simple Harmonic Motion  5.1.1. Equations of SHM  5.1.2. Energy in SHM  5.1.3. Damped and forced oscillations  5.1.4. Resonance and applications  5.1.5. Pendulum and spring-mass system  5.2. Wave motion  5.2.1. Types of mechanical waves  5.2.2. Wave motion and energy transport  5.2.3. Superposition Principle and Standing Waves  5.2.4. Reflection, Refraction and Diffraction  5.2.5. Doppler effect in sound and light  5.2.6. Pulsations and interference
  6. Electricity and Magnetism  6.1. Electrostatics  6.1.1. Electric charge and conservation  6.1.2. Coulomb's law and its applications  6.1.3. Electric field and electric flux  6.1.4. Electric potential and potential energy  6.1.5. Capacitance and Energy Stored in a Capacitor  6.2. Current Electricity  6.2.1. Ohm's law and electrical resistance  6.2.2. Resistivity and temperature dependence  6.2.3. Kirchhoff's Laws and Circuit Analysis  6.2.4. Electrical power and efficiency  6.2.5. Combination of resistors  6.3. Magnetism and Electromagnetism  6.3.1. Magnetic fields and their sources  6.3.2. Magnetic force on moving charges  6.3.3. Electromagnetic induction  6.3.4. Faraday's and Lenz's laws  6.3.5. Inductance and Transformer  6.3.6. Alternating current and its applications
  7. Optics  7.1. Reflection and Refraction  7.1.1. laws of reflection and refraction  7.1.2. Mirrors and lenses  7.1.3. Total internal reflection and optical fiber  7.2. Wave optics  7.2.1. Interference and Diffraction  7.2.2. Young's double-slit experiment  7.2.3. Polarization of light
  8. Modern Physics  8.1.1. Photoelectric effect and Einstein's theory  8.1.2. Wave–particle duality  8.1.3. Heisenberg's uncertainty principle  8.1.4. Compton Effect  8.2. Atomic and Nuclear Physics  8.2.1. Atomic model and energy levels  8.2.2. Radioactive decay and half-life  8.2.3. Nuclear Fission and Fusion
  9. Electronics and Communication  9.1. Semiconductors  9.1.1. pn junction and diode  9.1.2. Transistors and Logic Gates  9.1.3. Integrated Circuits and Applications  9.2. Communication Systems  9.2.1. Basics of Analog and Digital Communication  9.2.2. Wireless and Optical Communication  9.2.3. Modulation and Demodulation

Grade 11 → Thermal physics ↓


Heat and temperature


In thermal physics, heat and temperature are fundamental concepts that describe the behavior of energy and matter. These concepts help us understand how energy is transferred and how it affects the state and properties of substances. Although they are often used interchangeably in everyday language, heat and temperature are different physical quantities that have different meanings.

Withstanding temperature

Temperature is a measure of the average kinetic energy of the particles in a substance. It is a scalar quantity, which means it has magnitude but no direction. When we say that an object or substance is hot or cold, we are usually referring to its temperature.

Temperature can be measured using different scales. The most common scales are the Celsius, Kelvin, and Fahrenheit scales.

Temperature scale

Celsius

The Celsius scale is based on the freezing and boiling points of water at standard atmospheric pressure, which are 0°C and 100°C, respectively.

Kelvin

The Kelvin scale is the SI unit of temperature and is used in scientific contexts. It starts at absolute zero, which is the theoretical point where particles have the minimum thermal motion. Temperatures in Kelvin can be calculated from Celsius as follows:

T(K) = T(°C) + 273.15
0 °C / 273.15K 100°C / 373.15K

Fahrenheit

The Fahrenheit scale is used primarily in the United States. The freezing point of water is 32°F, and the boiling point is 212°F. The conversion between Celsius and Fahrenheit is given as follows:

T(°F) = T(°C) × 9/5 + 32
32°F 212°F

Understanding the heat

Heat is a form of energy that is transferred between systems or objects with different temperatures. Unlike temperature, heat is not a property of an object or system, but a process of energy transfer. Heat flows from a hotter object to a cooler object and may cause a change in the temperature or state of the substances involved.

Heat transfer

There are three primary modes of heat transfer: conduction, convection, and radiation.

Conductivity

Conduction is the transfer of heat through direct contact between the molecules of a substance. It occurs mainly in solids. An example is a metal rod being heated at one end, causing heat to flow to the other end.

heat flow by conduction

Convection

Convection is the transfer of heat by the movement of a fluid (liquid or gas). It occurs when hotter areas of a liquid or gas move towards cooler areas of the fluid. An example of this is boiling water, where hotter water from the bottom rises to the surface.

convection currents in water

Radiation

Radiation is the transfer of heat in the form of electromagnetic waves. It does not need a medium to travel, so it can occur in a vacuum. The transfer of heat from the Sun to the Earth is an example of radiation.

heat by radiation

Relation between heat and temperature

While heat and temperature are related, they are not the same thing. Temperature is a measure of the average kinetic energy of particles, while heat is the total energy transferred as a result of a temperature difference. Heat transfer can change the temperature of an object, but the amount of heat needed to change the temperature depends on several factors, including the mass of the substance and its specific heat capacity.

Specific heat capacity

Specific heat capacity is the amount of heat required to change the temperature of a unit mass of a substance by one degree Celsius. It is an intrinsic property that varies with different materials. The formula for heat added or removed is:

Q = m × c × ΔT

Where:

  • Q is the heat transferred (in joules).
  • m is the mass of the substance (in kilograms).
  • c is the specific heat capacity of the substance (in joules/kg°C).
  • ΔT is the change in temperature (in Celsius).

Example

Let's consider an example to illustrate this relationship. If you have a vessel of water and a metal rod, both at room temperature, and you supply the same amount of heat to both, the temperature of the water will rise less than that of the metal rod. This is because water has a higher specific heat capacity than the metal, which means it requires more heat to raise its temperature.

Imagine another scenario: you have a piece of ice at 0°C that you heat up by turning on the stove. Initially, all the heat goes into melting the ice without changing its temperature, which shows that energy transfer is not always the result of a temperature change.

Practical applications

Understanding heat and temperature is important in many fields, such as cooking, construction, climate technology, and even in the design of everyday appliances.

Cooking

Cooking involves transferring heat to food to change its temperature and state. For example, knowing the specific heat capacity of water helps to understand how much energy is needed to boil or cool it.

Building and construction

Building materials are selected based on their thermal properties. Insulation materials are used to reduce heat loss or gain, improving energy efficiency and comfort in buildings.

Climate and weather

Climatology often involves the study of how heat from the sun is transferred through the Earth's atmosphere and oceans, which plays a role in weather patterns and climate change.

Technology and equipment

Thermal management in electronics, such as phones and computers, is crucial to maintaining performance and ensuring longevity. Devices are designed to dissipate heat efficiently, reducing overheating and potential damage.

Conclusion

In conclusion, heat and temperature are fundamental concepts in understanding how energy is transferred and used in various materials and processes. Temperature represents the average energy of the motion of particles in a substance, while heat describes the energy transferred between objects due to temperature differences. Understanding these ideas provides essential insights into the physical world, which impacts a variety of scientific, industrial, and everyday life applications.


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Heat and temperature

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