Chapter 15 - Sound Flashcards
Rarefaction are regions where ______ is slightly lower than _________
Air pressure, surrounding pressure
The air particles do NOT move from one end to another, they only_______
Vibrate about their Mean position within their region
For sound waves, one wave length is the distance between two consecutive ______ and ______
Compression and rarefaction
The maximum pressure change in sound wave give the ________
Amplitude
How the bell jar experiment show that sound cannot travel in vacuum
When the vacuum pump is off and the electric bell is on and striking the bell, air is present inside the glass jar and sound of the striking can be heard.
When the vacuum pump is off and electric bell is STILL on and striking the bell. The air inside the glass jar is drawn out and inside the glass jar is vacuum. Sound is then could not be heard.
Speed of sound is not a _______, it varies according to _______ in which it is traveling. Generally fastest in______ and slowest in _______
Constant, Medium, Solid, Gas
Speed of the sound depends on some physical conditions, what are those?
Temperature, higher, faster
Humidity, higher, faster
Presence of wind, if sound is travel in the opposite direction of the wind, speed of the sound decrease
Speed of sound =
Distance travelled by the sound / Time taken for the sound to reach that spot
Sound waves obey the law of reflection, where ________ is equal to ________
Angle of incidence = angle of reflection
Speed of the sound is changed after reflection
NO.
Distinct reflected sound is known as ______
Echo
The effect of prolonged sound due to the merging of many echo is know as a _______
Reverberation
Good echoes are produced when? (3)
The distance between source and reflector is long enough
The area of the reflector is large enough
The frequency of the incident sound is high enough
Use of echo
Sonar is used by the ships to determine the depth of the sea bed
Sound above 20,000 Hz is known as_______
Ultrasound
