The process of pumping water to a higher elevation, is equivalent to what process in nature? *

Altitude may aid or diminish a pump's performance based upon the principals of specific gravity, atmospheric pressure, and oxygen deprivation.  

Specific Gravity & Atomospheric Pressure Based Upon Altitudes

Specific gravity suggests water can be pumped from less than or equal to 26 feet down when operating a pump at sea level because of atmospheric pressure.  This depth lessens as altitude increases because of decreasing atmospheric pressures. For every 1,000 feet above sea level that a centrifugal pump is operated, subtract an estimated two feet from the depth of 26 feet.  Pump operators will be well served to locate their pump as close to the source of water you are pumping as practically possible.  

Elevation Impacts To Suction Lift

Explanation:

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

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