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A triangular plate is shown. A force vec...

A triangular plate is shown. A force `vec( F ) = 4 hat(i) - 3 hat(j)` is applied at point P. The torque at point P with respect to point 'O' and 'Q ' are `:`

A

`-15+20sqrt(3),15+20sqrt(3)`

B

`-15-20sqrt(3),15-20sqrt(3)`

C

`15+20sqrt(3),15-20sqrt(3)`

D

`15-20sqrt(3),15+20sqrt(3)`

Text Solution

Verified by Experts

The correct Answer is:
B

`vec(tau)=vec(r)xxvec(F)`
`vec(tau_(Q))=(5hat(i)+5sqrt(3)hat(j))xx(4hat(i)-3hat(j)),`
`vec(tau_(Q))=(-15-20sqrt(3))hat(k),`
`vec(tau_(R))=(-5hat(i)+5sqrt(3)hat(j))xx(4hat(i)-4hat(j)),`
`vec(tau_(R))=(15-20sqrt(3))hat(k)`
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