The answer is D, because the collision's between molecules are elastic, not inelastic.
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C) heat from the sun
Why?
Because the sun’s heat makes the water turn to steam—or what we call “water vapor.”
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Answer:
Coefficient of friction.
Explanation:
The amount of friction divided by the weight of an object is equal to the coefficient of friction. It is a dimensional less number. It can be given by :

N is normal force.
= coefficient of friction
