Explanation:
It is given that,
Force applied to object, [tex]F=(2i+3j)\ N[/tex]
Position, [tex]r=(4i+5j)\ m[/tex]
(b) The cross product of force and position vector is used to find the net torque about the z axis. It is given by :
[tex]\tau=F\times r[/tex]
[tex]\tau=(2i+3j) \times (4i+5j)[/tex]
[tex]\tau=\begin{pmatrix}0&0&-2\end{pmatrix}[/tex]
or
[tex]\tau=(-2k)\ N-m[/tex]
The torque is acting in -z axis.
(a) The magnitude of torque is given by :
[tex]|\tau|=\sqrt{(-2)^2}[/tex]
[tex]|\tau|=2\ N-m[/tex]
Hence, this is the required solution.
