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 ↓


Specific heat capacity and calorimetry


Understanding the concepts of specific heat capacity and calorimetry is fundamental in thermal physics. These concepts help us understand how substances absorb and release heat. This guide will discuss these topics in detail, providing both theoretical insights and practical examples.

What is heat?

Heat is a form of energy that flows from a hotter object to a colder object. It is measured in joules (J) and is related to the total kinetic energy of the particles in a substance. When an object absorbs heat, its particles vibrate and move faster, causing the object's temperature to increase. Temperature is a measure of the average kinetic energy of the particles in a substance.

Specific heat capacity

Specific heat capacity is the amount of heat energy needed to raise the temperature of one kilogram of a substance by one degree Celsius. It is represented by the symbol c and is measured in joules per kilogram per degree Celsius (J/kg°C).

The formula for calculating specific heat capacity is:

c = Q / (m * ΔT)

Where:

  • c is the specific heat capacity.
  • Q is the amount of heat energy added or removed (in joules).
  • m is the mass of the substance (in kilograms).
  • ΔT is the change in temperature (in degrees Celsius).

Example:

Imagine you have a 2-kilogram block of aluminum, and you impart 1800 joules of heat energy to it. If the temperature of the block rises by 5°C, what is the specific heat capacity of aluminum?

Given: Q = 1800 J m = 2 kg ΔT = 5°C c = Q / (m * ΔT) c = 1800 / (2 * 5) c = 180 J/kg°C

The specific heat capacity of aluminium is 180 J/kg°C.

Visual example:

Aluminum Block Mass = 2 kg ΔT = 5°C

Factors affecting specific heat capacity

Specific heat capacity is affected by the following factors:

  • Type of material: Different materials require different amounts of energy to change the temperature.
  • State of Matter: The specific heat capacity of solids, liquids and gases differ due to the spacing between their molecules.

Calorimetry

Calorimetry is the science of measuring the amount of heat transferred in a chemical reaction or change of state. It involves using a special container called a calorimeter to measure heat flow with minimal interference from the surrounding environment.

Principle of calorimetry

The principle behind calorimetry is that the heat lost by a hot object is equal to the heat gained by a cold object, provided there is no loss to the surroundings:

Q_lost = Q_gained

In a calorimetry experiment, if a hot object is placed in cold water, the heat lost by the object is equal to the heat gained by the water:

m_hot * c_hot * ΔT_hot = m_cold * c_cold * ΔT_cold

Example:

Suppose a piece of metal of mass 0.5 kg is heated to 100°C and then immersed in 1 kg of water at 20°C. If the final temperature of the water-metal system is 25°C, find the specific heat capacity of the metal. Assume that there is no heat loss to the environment.

Heat lost by metal = Heat gained by water m_metal * c_metal * (T_initial - T_final) = m_water * c_water * (T_final - T_initial) 0.5 * c_metal * (100 - 25) = 1 * 4.18 * (25 - 20) 37.5 * c_metal = 20.9 c_metal = 20.9 / 37.5 c_metal ≈ 0.56 J/g°C

Visual example:

Metal water in the calorimeter

Measuring heat transfer

To measure heat transfer in calorimetry, the heat capacity of the calorimeter may need to be considered. If the heat capacity of the calorimeter is C, then any experiment will follow this principle:

Q_system = Q_water + Q_calorimeter

where Q_calorimeter accounts for the heat absorbed or released by the calorimeter.

Applications of Calorimetry

Calorimetry is used in many fields, including chemistry, biology, and engineering. Some applications include:

  • Determination of specific heat: As shown in the examples, calorimetry can be used to determine the specific heat capacity of unknown substances.
  • Measuring heat of reaction: It helps in determining the enthalpy change in chemical reactions.
  • Food industry: Used to assess the energy content in foods by measuring the heat emitted during combustion.

Understanding Thermal Equilibrium

When two objects are in contact and reach the same temperature, they achieve thermal equilibrium. This concept is important in calorimetry, because it assumes that when equilibrium is achieved, no heat is transferred between the objects.

The importance of accurate measurements

In calorimetry experiments, the accuracy of measurements is crucial. Inaccurate measurements of mass, temperature or heat capacity can lead to incorrect calculations and conclusions. This highlights the importance of using accurate instruments and methods.

Overall, specific heat capacity and calorimetry are important concepts in understanding how heat is absorbed, transferred, and conserved in various materials and systems. By applying these concepts, we gain information about the thermal properties of substances, which helps us develop technology, create new materials, and better understand natural processes.


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Specific heat capacity and calorimetry

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