What is the torque of force $\vec F = 2\hat i - 3\hat j + 4\hat k$ acting at a point $\vec r = 3\hat i + 2\hat j + 3\hat k$ about the origin?

The center of an equilateral triangle $ABC$ is $O$. Three forces $F_1$,$F_2$,and $F_3$ are applied along the sides $AB$,$BC$,and $AC$ respectively. If the total torque about $O$ is zero,what is the relationship between $F_1$,$F_2$,and $F_3$?

The moment of inertia of a disc of radius $0.5\,m$ about its geometric axis is $2\,kg-m^2.$ If a string is tied to its circumference and a force of $10\,N$ is applied,the value of torque with respect to this axis will be ........ $N-m.$

$A$ door $1.2 \,m$ wide requires a force of $1 \,N$ to be applied perpendicularly at the free end to open or close it. The perpendicular force required at a point $0.2 \,m$ distant from the hinges for opening or closing the door is: (in $\,N$)

$A$ force $\vec{F} = 4\hat{i} + 3\hat{j} + 4\hat{k}$ is applied at the intersection point of the plane $x = 2$ and the $x$-axis. The magnitude of the torque of this force about the point $(2, 3, 4)$ is .......... . (Round off to the nearest integer)

$A$ force $F_1 = A \hat{j}$ is applied to a point whose radius vector is $r_1 = a \hat{i}$, while a force $F_2 = B \hat{i}$ is applied to the point whose radius vector is $r_2 = b \hat{j}$. Both the radius vectors are determined relative to the origin of the coordinate axes $O$. The moment of the force relative to $O$ is