Sound and Light Wave Properties

Mechanical Wave: A disturbance of a medium that transfers energy from one location to another without net movement of matter.
Longitudinal Waves: Particles move parallel to the wave's motion (e.g., sound waves). These consist of:
- Compressions: Sections where particles are closer together than average.
- Rarefactions: Sections where particles are further apart than average.
Transverse Waves: Particles move perpendicular to the wave's motion (e.g., light waves, ripples in a pond).
Sound Transmission: Sound is a form of energy made by vibrations. It travels fastest through solids where molecules are closer together and cannot travel through empty space (vacuum).

Wavelength (\$\$\lambda\$\$): The distance between two consecutive compressions or rarefactions.
Amplitude (\$\$A\$\$): The maximum magnitude of pressure variation from undisturbed pressure.
Period (\$\$T\$\$): The time taken in seconds for one complete cycle.
Frequency (\$\$f\$\$): The number of complete cycles per second, measured in Hertz (\$\$Hz\$\$).
Inverse Relationship: \$\$f = \frac{1}{T}\$\$.
Pitch: High-pitched sounds have high frequency; low-pitched sounds have low frequency.
Wave Equation:
- \$\$v = f \times \lambda\$\$
- \$\$v = \text{wave speed (m/s)}\$\$
- \$\$f = \text{frequency (Hz)}\$\$
- \$\$\lambda = \text{wavelength (m)}\$\$
Example Calculation: if sound travels \$\$119\,m\$\$ in \$\$0.35375\,s\$\$:
- \$\$v = \frac{\text{distance}}{\text{time}} = \frac{119\,m}{0.35375\,s} = 336\,m/s\$\$

Speed: Light travels much faster than sound at approximately \$\$300,000\,km/s\$\$. At this speed, it can circle the Earth \$\$7.5\$\$ times in one second.
Propagation: Light travels in straight lines. Shadows are formed when light is blocked by an object.
Objects and Materials:
- Luminous: Objects that produce light (e.g., the Sun, fire, light bulbs).
- Non-luminous (Reflectors): Objects that reflect light (e.g., mirrors, water).
- Transmission: Materials are classified as transparent, translucent, or opaque based on how light travels through them.
Rays and Beams: A single light ray shows the path of light; a stream of rays is called a beam.

Electromagnetic (EM) Waves: Pulses of electrical and magnetic energy that propagate through a vacuum at the speed of light.
Order (Increasing Frequency and Energy / Decreasing Wavelength):
1. Radio waves
2. Microwaves
3. Infrared
4. Visible light (\$\$700\,nm\$\$ to \$\$400\,nm\$\$)
5. Ultraviolet
6. X-rays
7. Gamma rays

Law of Reflection: The angle of incidence equals the angle of reflection.
Mirror Types:
- Concave: Bulging inwards; a converging mirror.
- Convex: Bulging outwards; a diverging mirror.
Reflection Quality:
- Clear: Light reflects from smooth, shiny surfaces.
- Diffuse: Light is scattered in different directions by rough, dull surfaces.
Refraction: The bending of light as it moves between transparent substances of different speeds.
Color Addition (Primary colors of light: Red, Blue, Green):
- \$\$\text{Red} + \text{Blue} + \text{Green} = \text{White}\$\$
- \$\$\text{Red} + \text{Green} = \text{Yellow}\$\$
- \$\$\text{Blue} + \text{Green} = \text{Cyan}\$\$

Mechanical Wave: A disturbance of a medium that transfers energy from one location to another without net movement of matter.
Longitudinal Waves: Particles move parallel to the wave's motion (e.g., sound waves). These consist of:
- Compressions: Sections where particles are closer together than average.
- Rarefactions: Sections where particles are further apart than average.
Transverse Waves: Particles move perpendicular to the wave's motion (e.g., light waves, ripples in a pond).
Sound Transmission: Sound is a form of energy made by vibrations. It travels fastest through solids where molecules are closer together and cannot travel through empty space (vacuum).

Wavelength ( $\lambda$ ): The distance between two consecutive compressions or rarefactions.
Amplitude ( $A$ ): The maximum magnitude of pressure variation from undisturbed pressure.
Period ( $T$ ): The time taken in seconds for one complete cycle.
Frequency ( $f$ ): The number of complete cycles per second, measured in Hertz ( $Hz$ ).
Inverse Relationship: $f = \frac{1}{T}$ .
Pitch: High-pitched sounds have high frequency; low-pitched sounds have low frequency.
Wave Equation:
- $v = f \times \lambda$
- $v = \text{wave speed (m/s)}$
- $f = \text{frequency (Hz)}$
- $\lambda = \text{wavelength (m)}$
Example Calculation: if sound travels $119\,m$ in $0.35375\,s$ :
- $v = \frac{\text{distance}}{\text{time}} = \frac{119\,m}{0.35375\,s} = 336\,m/s$

Speed: Light travels much faster than sound at approximately $300,000\,km/s$ . At this speed, it can circle the Earth $7.5$ times in one second.
Propagation: Light travels in straight lines. Shadows are formed when light is blocked by an object.
Objects and Materials:
- Luminous: Objects that produce light (e.g., the Sun, fire, light bulbs).
- Non-luminous (Reflectors): Objects that reflect light (e.g., mirrors, water).
- Transmission: Materials are classified as transparent, translucent, or opaque based on how light travels through them.
- Rays and Beams: A single light ray shows the path of light; a stream of rays is called a beam.