Major players in the drama of 19th-century Texas were definitely the Comanches who at this time swept down from the cool highlands of the southern Rockies, and, mounted on horses, drove other tribes from West Texas.
What is SOUND? The periodic mechanical vibrations and waves in gases, liquids and solid elastic media. Specifically the sensation felt when the eardrum is acted upon by air vibrations within a limited frequency range, ie 20 Hz to 20 kHz. Sound of a frequency below 20 Hz is called infra. STRUCTURE-BORNE SOUND.
The definition of sound says that it is a disturbance of energy that comes through matter as a wave, and that humans perceive sound by the sense of hearing. Sound pressure is the effect and sound power (energy) is the cause.But our eardrums are only sensitive to the sound pressure, and so are microphone diaphragms.he energy in a sound wave is both kinetic and potential. Just as in a vibrating spring, the medium has mass a â¦ nd moves and so moving mass is kinetic energy. Just as in the spring there is compression and rarefaction, so there is elastic potential energy.