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The work done in moving an object from o...

The work done in moving an object from origin to a point whose position vector is `r=3hati+2hatj-5hatk` by a force `F=2hati-hatj-hatk`

A

1 unit

B

9 unit

C

13 units

D

60 units

Text Solution

Verified by Experts

The correct Answer is:
b
Workdone,W=F.r
`F=2hati-hatj-hatk`
`r=3hati+2hatj-5hatk`
Vector identify, `hati.hati=hatj.hatj=hatk.hatk=1`
`w=(2hati-hatj-hatk).(3hati+2hatj-5hatk)`
=6-2+5=9units
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