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Let a force F be acting on a body free t...

Let a force F be acting on a body free to rotate about a point O and let r the position vector of any point P on the line of action of the force. Then torque `(tau)` of this force about point O is defined as ` tau = rxxF` Given, `F = (2hati + 3hatj - hatk)N and r = (hati- hatj+6hatk)m` Find the torque of this force.

Text Solution

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`vectau = vecr xx vecF =|( hati, hatj,hatk),( 1,-1,6),(2,3,-1)|= hati (1-18 ) + hatj ( 12 +1 ) hatk (3 +2)`
` vectau =(-17 hati + 13 hatj +5 hatk ) N-m`
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