Sound - Class 10 ICSE Syllabus

Pitch of Sound

• The pitch of a sound is determined by its frequency; higher frequencies result in higher pitches, while lower frequencies produce lower pitches.
• Frequency is measured in hertz (Hz), indicating the number of wave cycles per second.

Bending of Sound Waves

• The bending of sound waves is primarily caused by refraction, which occurs when sound travels through different mediums or changes in temperature.
• Refraction leads to a change in wave speed and direction as the sound waves enter a medium with a different density.

Temperature and Sound Speed

• Generally, as temperature increases, the speed of sound in air also increases. This is due to faster-moving air molecules transmitting sound waves more quickly.
• The speed of sound in air is approximately 0.6 meters per second for every degree Celsius rise in temperature.

Sound in a Vacuum

• Sound cannot travel through a vacuum because it requires a medium (solid, liquid, or gas) to propagate; in a vacuum, there are no molecules to carry the sound waves.
• As a result, sound is silent in space where a vacuum exists.

Wave Cycle Time

• The term "period" describes the time taken for one complete wave cycle to pass a point.
• The period is the reciprocal of frequency; a higher frequency corresponds to a shorter period.