Waves. Mechanical and electromagnetic waves

Waves are disturbances that propagate through space and time, carrying energy with no net transport of matter. They are fundamental phenomena found in many branches of physics, such as optics, acoustics, electromagnetism and mechanics. Waves can be classified into two main categories: mechanical waves and electromagnetic waves.

Mechanical waves require a material medium to propagate. For example, sound waves are mechanical waves that propagate through the vibration of particles in a medium, such as air, water or solids. Other examples of mechanical waves include waves on a taut string, seismic waves on Earth, and waves in the ocean.

Electromagnetic waves, on the other hand, do not require a material medium to propagate and can move through a vacuum. These waves are composed of oscillating electric and magnetic fields that propagate perpendicular to each other. Visible light, radio waves, X-rays and microwaves are examples of electromagnetic waves.

Waves are described by several characteristics. Wave amplitude is the maximum distance that particles move from their equilibrium position. Wavelength is the distance between two equivalent points on the wave, such as two consecutive crests or two consecutive valleys. Frequency is the number of oscillations that occur per unit time and is measured in hertz (Hz).