6 degrees
4N
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Sound waves in air (and any fluid medium) are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves.
The total momentum before a collision is equal to the total momentum after the collision if no external forces act on the system.
Hope this helps
Water in the Earth system is influencing all aspects of life on Earth. ... The returning water falls directly back into the oceans, or onto land as snow or rain. It soaks into the soil to move into the groundwater or runs off the Earth's surface in streams, rivers and lakes, which drain back into the oceans.