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CBSE Class 9 Answered

Give an example where work done is negative?
Asked by Manu shrivastava | 09 Dec, 2013, 10:41: PM
answered-by-expert Expert Answer
Work done W = Fd cos θ
 
when the direction of force and displacement are opposite, θ = 180,    cos 180 = -1
Hence W = -Ve
 
Example:
 
The falling body experiences a upwards drag force due to air resistance. Since the the drag force is being applied in the direction opposite to that of the motion, it's said to be doing negative work on the body.
Answered by Komal Parmar | 10 Dec, 2013, 06:58: AM

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