High task repitition, forceful exertions, repetitive or sustained awkward posture
Answer:0.318 revolutions
Explanation:
Given
Initially Propeller is at rest i.e. 
after 

using 


Revolutions turned in 2 s



To get revolution 
=
I believe the answer is Nonmaterial Culture.
Answer:
i cant solve this!
Mybe i can solve another question!
Answer: The answer is density