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A man standing with a load on his head o...

A man standing with a load on his head or a man walking with load does no work scientifically.

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Because a man standing with a load on his head exerts force on the load in upward direction but that load has no displacement in the direction of force (in upward direction). Hence as per `W=Fs=Fxx0=0`, work done on the load is zero. So it can be said that aman standing with the load on his head does no work.
Now, if the man with load is walking even though the man does no work on the load, because the man is exerting force on the load in upward direction, while as his motion is in horizontal direction, his displacement is in the horizontal direction. So, as the angle between the force and displacement is `90^(@)`, there is no work done on the load as per `W=F_(1)xxs=0xxs=0`.
Where, `F_(1)` = Effective force along direction of dispalcement.
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