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 → Waves and oscillations → Wave motion ↓


Wave motion and energy transport


In the fascinating world of physics, wave motion presents an exciting phenomenon. Waves are fascinating because they encompass a wide variety of phenomena that occur in different mediums such as air, water, and even solids. Two very important aspects of wave study are wave motion and energy transport. These concepts are central to understanding how waves travel through different mediums and how they carry energy from one place to another. Throughout this lesson, we will discuss these concepts using simple language to ensure that you understand the essence of wave motion and energy transport.

Understanding waves

Before diving into wave motion and energy transport, it is necessary to understand what a wave is. A wave is a disturbance that travels through a medium, transferring energy from one point to another without causing any permanent displacement of the medium. Waves can take various forms, but they generally fall into two main categories: mechanical waves and electromagnetic waves.

Mechanical waves

Mechanical waves require a medium to travel and can be classified as transverse or longitudinal. Water waves and sound waves are common examples of mechanical waves.

  • Transverse Waves: In these waves the particles of the medium move perpendicular to the direction of wave propagation. A great example is a wave traveling on a string.
  • Longitudinal Waves: In these waves the particles of the medium vibrate parallel to the direction of wave propagation. Sound waves travelling through air are a classic example of this.

Electromagnetic waves

Electromagnetic waves do not require any medium to propagate. They travel in the vacuum of space. Light, radio waves and microwaves fall into this category. They are always transverse waves.

Wave motion

Wave speed is an important concept in wave motion. It tells us how fast a wave travels through a medium. Wave speed is defined as the distance travelled by the wave per unit time. The formula used to calculate wave speed is:

v = fλ

Where:

  • v is the speed of the wave
  • f is the frequency of the wave
  • λ (lambda) is the wavelength

Frequency and wavelength

Let's dig a little deeper into these parameters. Frequency refers to how many wave cycles pass a specific point in one second. It is measured in Hertz (Hz). Wavelength, on the other hand, is the distance between successive points of the wave that are in phase, such as peak to peak or trough to trough. Wavelength is measured in meters (m).

For example, imagine gentle waves on the beach. If a wave travels from one peak to another, covering a distance of 4 meters, with a frequency of 2 Hz, the wave speed would be calculated as:

v = fλ = 2 Hz × 4 m = 8 m/s

Visualization of wave motion

Let's imagine a simple transverse wave to understand how wave motion works. Imagine a rope tied at one end and you are shaking the free end up and down.

Crest Trough

Factors affecting wave speed

Wave speed can be affected by a number of factors. For mechanical waves, the properties of the medium, such as density and elasticity, play an important role. For example, sound travels more quickly in water than in air. For electromagnetic waves, the medium (or lack thereof) also affects speed, with light traveling more slowly in glass than in air.

Energy transport in waves

Waves aren't just fascinating because they travel; they move and transport energy from one place to another. This property is important for many natural and technological processes.

Energy in mechanical waves

Energy in mechanical waves is related to the amplitude of the wave. Waves with higher amplitudes carry more energy. Consider waves crashing on a shore. On a stormy day, the waves are larger and carry more energy than the gentle waves of a calm day.

Energy in electromagnetic waves

For electromagnetic waves, the energy depends on the frequency as well as the amplitude. For example, gamma rays have more energy than radio waves because their frequency is higher, despite possibly having the same amplitude.

Visualization of energy transportation

Another way to understand energy transport is to imagine energy flow in a wave. Consider a slinky that you stretch and then create a pulse by sending rapid compressions down its length.

Pressure

Real-life examples of energy transport

Some real-life examples of energy transport via waves include:

  • Sound waves: When a guitar string vibrates, it moves air particles around it, creating compressions and rarefactions that reach your ears, allowing you to hear music.
  • Sea Waves: The energy brought by sea waves can be used to generate electricity through turbines.
  • Microwaves in the oven: Microwaves deliver energy to the water molecules in food, causing them to vibrate and heat the food.

Conclusion

Wave motion and energy transport are fundamental aspects of wave behavior. Understanding these concepts provides insight into how waves work and interact with the environment. Waves are an integral part of our everyday lives, from the light that helps us see to the sound that enables communication. Through this exploration of waves, we gain a deeper appreciation for the complex dance of energy and motion that shapes the physical world.


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Wave motion and energy transport

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