It must have a medium. It must travel in empty space. Mechanical waves are waves which needs medium of propogation.
Answer:
the ionosphere
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The zone that gases always accelerate upward is the Luminous flame zone. The fire plume is the column of hot gases, flames and smoke rising above a fire. Gases accelerate upward toward the always luminous flame zone. The luminous flame height is the distance between the base of a flame and the point at which the plume is luminous half the time and transparent half the time.
Answer:
Check the diagram from the photo
Explanation:
