Sound Waves: Characteristics and Applications Mind Map

Sound is produced when an object vibrates and sets the surrounding medium into vibration.

In observation-based answers, always mention the vibrating part, such as prongs of tuning fork, drum membrane, or vocal cords.

Propagation of sound is the travelling of sound energy through a material medium by successive compressions and rarefactions.

For propagation answers, include three words: medium, compression, rarefaction.

Sound in air is a longitudinal mechanical wave because medium particles vibrate parallel to the direction in which the wave travels.

When asked why sound is longitudinal, compare particle vibration direction with wave travel direction.

Wave characteristics are measurable features of a wave, mainly wavelength, frequency, time period, and amplitude.

Write units carefully: wavelength in metre, frequency in hertz, time period in second, and amplitude in metre.

The wave speed relation states that speed of a wave equals frequency multiplied by wavelength, written as v = fλ.

Write the formula first, substitute with units, and check whether the final unit is m/s, Hz, or m.

Loudness depends mainly on amplitude of vibration, while pitch depends mainly on frequency of vibration.

For loudness mention amplitude; for pitch mention frequency. Do not interchange them in one-mark answers.

Audible range is the range of frequencies that humans can normally hear, about 20 Hz to 20,000 Hz.

Write the numerical range with units: 20 Hz to 20,000 Hz. Then classify below as infrasound and above as ultrasound.

Reflection of sound is the bouncing back of sound from a surface; echo is a distinct reflected sound, while reverberation is repeated reflection that prolongs sound.

For echo numericals, always use total distance travelled by sound = 2 × distance from wall.

Ultrasound applications use sound waves of frequency above 20,000 Hz for detection, imaging, cleaning, navigation, and measuring distances.

For application answers, mention transmitted ultrasound, reflected echo, and calculation or image formation from the return signal.