Answer:
[tex]\tau = - 30 \hat k[/tex]
Explanation:
Position vector of the point of application of point of application of force is given as
[tex]\vec r = 2\hat i + 2\hat j[/tex]
now we have have force
[tex]\vec F = 5 \hat i - 10\hat j[/tex]
now the moment of force is given as
[tex]\tau = \vec r \times \vec F[/tex]
[tex]\tau = (2\hat i + 2\hat j) \times (5\hat i - 10\hat j)[/tex]
[tex]\tau = -20\hat k - 10 \hat k[/tex]
[tex]\tau = - 30 \hat k[/tex]