Understanding Wave Physics: Characteristics and Interactions

What is a Wave?

A wave (k) is a perturbation that transports energy, originating from a periodic disturbance. Waves exhibit several key characteristics:

• Frequency: The number of wavelengths or impulses passing a point per unit of time.
• Wavelength: The distance traveled by the wave during one cycle.

Waves extend in all directions. When they encounter an obstacle, they undergo:

• Reflection: A change in direction.
• Refraction: If they enter the obstacle, their speed changes.

Kinds of Mechanical Waves

Waves can be classified based on their origin:

Mechanical Waves

These require a medium to propagate. A sudden pressure change can cause them.

Electromagnetic Waves

These occur due to electrical and magnetic disturbances.

The speed of a wave depends on its nature and the medium it travels through.

Sound Waves

Sound waves can experience:

• Attenuation: This occurs due to the distribution of wave energy over an increasing volume of air.
• Damping: This happens when the medium through which the sound propagates retains part of its energy.

Characteristics of Sound

• Strength (Loudness): Relates to the difference between bass and treble sounds.
• Tone (Pitch): Depends on the frequency of the sound, distinguishing between low and high pitches.
• Timbre (Ringer): The difference between voices or musical sounds.

Light Waves

Light is characterized by outbreaks, although they are not particles like atoms.

Light Spectra

Sources that emit waves of different frequencies are called spotlights. The spectrum of higher frequency light is called ultraviolet (beyond violet). White light is a mixture of all colors.

Interaction Between Light and Material

Materials behave differently when interacting with light:

• Opaque: Do not let light pass through.
• Translucent: Let only some light pass through.
• Transparent: Let most light pass through, allowing clear visibility.

Light undergoes propagation processes such as reflection, refraction, and attenuation.

Reflection of Light

Reflection of light can be:

• Specular Reflection (Mirror): Occurs on very smooth surfaces, allowing reflected images to be seen.
• Diffuse Reflection: Occurs on most surfaces and does not allow for clear reflected images.

Formation of Shadows

Shadows are an effect of the rectilinear propagation of light. We see shadows because specular reflection occurs.

Refraction of Light

Light is deflected when it enters a transparent medium because its speed of propagation changes.

Absorption of Light and Colors

The color of a material depends on which photons it absorbs and reflects:

• Materials we see as white reflect all light.
• Materials we see as black absorb all light.

Daltonism: The inability to distinguish colors.