The intensity of sound is measured in terms of the amount of power that passes each second through a given area perpendicular to the direction of the sound wave. The intensity unit is the decibel (db).
Velocity. Sound can be transmitted by any medium — gas, liquid, or solid — and all sound waves travel at a constant velocity through any given medium at a constant temperature. But depending on their elasticity and density, some mediums transmit waves faster than others.
The velocity of sound is affected by temperature; as the temperature increases, the medium expands. Its density decreases, with the result that the velocity of sound increases.
2.4. Найдите предложение, содержание которого не соответствует теме и смыслу текста.
1. A sound wave consists of a series of alternate compressions and rarefactions of the medium through which it passes.
2. Waves of alternate compression and rarefaction transmit kinetic energy through a medium.
3. As people grow older, their ability to perceive high frequencies diminishes
4. There are two types of waves in physics: longitudinal and transverse.
5. Solar energy is an alternative source of energy.
2.5. Найдите перевод словосочетаний на английский язык в тексте:
1. кожа барабана ________________________________________________
2. струны скрипки ______________________________________________
3. продольная волна ____________________________________________
4. человеческое ухо _____________________________________________
5. постоянная температура ______________________________________
6. эластичность и плотность ____________________________________
7. частотный диапазон __________________________________________
8. частота звуковой волны ______________________________________
9. скорость звука ________________________________________________
10. плотность среды _____________________________________________
11. частота звука ________________________________________________
2.6. Вставьте в пропуски предлоги: through/in/from, где необходимо.
1. Sound waves cannot pass _______ a vacuum.
2. All sounds originate _______ vibrating objects.
3. The vibrating objects are then passed on _______ a medium.
4. Frequency can be measured _______ physically.
5. The human ear is sensitive to sound _______ the frequency range ______ about 20 Hz.