Formula Sheet: SOUND

v is the speed of sound (in m/s), d is the distance traveled (in meters), and t is time taken (in seconds). This formula represents how sound travels through a medium.

f is frequency (in Hz), and T is the time period (in seconds). It indicates how many oscillations occur in one second.

v is the wave speed (in m/s), λ is the wavelength (in meters), and f is frequency (in Hz). This equation shows the relationship between the speed, wavelength, and frequency of sound.

λ is the wavelength (in meters), v is the speed of sound (in m/s), and f is frequency (in Hz). It is used to calculate the wavelength when speed and frequency are known.

T is the time period (in seconds) and f is frequency (in Hz). This formula calculates the time for one complete wave cycle.

L is loudness, and A is amplitude. The loudness is proportional to the square of the amplitude, indicating that a small increase in amplitude greatly increases the perceived loudness.

I is intensity (in W/m²), P is power (in watts), and A is area (in square meters). This formula defines the sound intensity as power per unit area.

d is distance (in meters), v is the speed of sound (in m/s), and t is time taken (in seconds) for an echo. This calculates the distance to a reflecting surface.

RT is the reverberation time (in seconds), V is the volume of the hall (in m³), and A is the total absorption (in m²). This formula estimates how long sound persists in a space.

Sounds with frequencies below 20 Hz are classified as infrasonic sound, which humans cannot hear but some animals can.

Sounds with frequencies above 20 kHz are classified as ultrasonic sound, which humans cannot hear but are used in various technologies.

This equation gives the speed of sound (in m/s) in air as a function of temperature (T in °C). It shows how temperature affects sound speed.

L is the sound level (in dB), I is the intensity of sound (in W/m²), and I₀ is the reference intensity (1 × 10⁻¹² W/m²). This formula is used for calculating sound intensity in decibels.

θi is the angle of incidence, and θr is the angle of reflection. This law shows that the angles of incidence and reflection are equal when sound reflects off a surface.

This equation relates frequency (f in Hz), speed of sound (v in m/s), and wavelength (λ in meters). It is essential for understanding wave behavior.

E is the energy (in joules) of a wave, h is Planck's constant (6.626 × 10⁻³⁴ Js), and f is frequency (in Hz). This applies to sound waves in context of quantum mechanics.