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A body constrained to move along the z-axis of a coordinate system is subject to a constant force F given by F=-i^+2j^+3k^NWhere i^,j^,k^ are unit vectors along the x-, y- and z-axis

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प्रश्न

A body constrained to move along the z-axis of a coordinate system is subject to a constant force F given by

`F = -hati+2hatj+3hatkN`

Where `hati,hatj,hatk` are unit vectors along the x-, y- and z-axis of the system respectively. What is the work done by this force in moving the body a distance of 4 m along the z-axis ?

संख्यात्मक
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उत्तर

Since the body is displaced 4m among z-axis only.

`:. hatS = 0hati +0hatj+4hatk`

Also `vecF = -hati +2hatj + 3hatk`

Work Done, `W  = vecF.vecS`

`= (-hati+2hatj+3hatk).(0hati+0hatj+4hatk)`

`= 12 (hatk.hatk)` joule = 12 Joule

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पाठ 5: Work, Energy and Power - EXERCISES [पृष्ठ ९०]

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एनसीईआरटी Physics Part 1 and 2 [English] Class 11
पाठ 5 Work, Energy and Power
EXERCISES | Q 5.11 | पृष्ठ ९०

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