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The torque of a force vecF=-3hati+hatj+5...

The torque of a force `vecF=-3hati+hatj+5hatk` acting at the point `vecr=7hati+3hatj+hatk` is

A

`14hati – 38hatj+16hatk`

B

`4hati+4hatj+6hatk`

C

`-21hati+4hatj+4hatk`

D

`-14hati+38hatj-16hatk`

Text Solution

Verified by Experts

The correct Answer is:
A
We know that, `bartau=barrxxbarF`
`thereforetau|(hati,hatj,hatk),(7,3,1),(-3,1,5)|`
= `hati(15-1)-hatj(35+3)+hatk(7+9)`
`vectau=14hati-38hatj+16hatk`
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