what is underground water??
Answers
Answer:
Groundwater, water that occurs below the surface of Earth, where it occupies all or part of the void spaces in soils or geologic strata. It is also called subsurface water to distinguish it from surface water, which is found in large bodies like the oceans or lakes or which flows overland in streams.
Answer:
Sound is just a vibration in the medium perceived by our ears as a consequence of the vibration of the air present inside them. We know this for a fact because if you ring a bell in a vacuum chamber, there is no sound as there is no medium to convey it.
Even in the presence of a medium if the vibration is not enough to disturb the air present inside our ears, we are not able to hear the sound. Or in other words if the frequency of the sound waves produced by the vibrating object is not in the audibe range, we are not able to perceive the sound.