Which is the best description of the cause of sound waves? a.a decrease in pressure
b.one object bumping into another
c.molecules becoming electrically charged
d. a vibration in material causing a vibration in an adjacent area

the answer is d

Explanation:

When we hear something, we are sensing the vibrations in the air. The number of vibrations per second is known as the frequency, measured in Hertz (1 Hz = 1 vibration per second).

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✅ Clear skies and Sunny.Explanation: ❗ Cold air is denser and thicker than warm air, so it usually sinks as warm air increases. Cold air sinks which causes a transient accumulation of water near the earth's area and thus an area with a high pressure in regions where winds meet at high altitude. With an increase in altitude air pressure reduces, so high pressure is in fact a relative concept. Weather forecasters commonly use this to signify high pressure relative to normal atmospheric pressures at that level.

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