Answer:
When force and displacement are in the same direction, the work performed on an object is said to be positive work. Example: When a body moves on the horizontal surface, force and displacement act in the forward path. The work is done in this case known as Positive work.
Explanation:
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B is the ans for this question
Answer:
The time interval is 
Explanation:
From the question we are told that
The constant acceleration is 
The displacement is
According to the second equation of motion we have that
given that the blade started from rest
which is the initial angular velocity is 0
So
=> 
substituting values
=> 
=> 