A force vecF=alphahati+3hatj+6hatk is ac...

A force `vecF=alphahati+3hatj+6hatk` is acting at a point `vecr=2hati-6hatj-12hatk`. The value of `.alpha.` for which angular momentum about origin is conserved is ……………

`-1`

zero

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Verified by Experts

The correct Answer is:

Law of conservation of moment about origin
`Sigmavectau=0`
`therefore vecrxxvecF=0`
`therefore alpha=-1" rad/s"^(2)`

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