Answer:
Therefore the magnitude of the applied force is
N.
Step-by-step explanation:
Torque: Torque is the cross product of force and the distance of applied force from the rotational axis.

Where
is angle between F and r.
Newton-meter is the S.I unit of torque.
Along the positive y axis, the wrench lies .
The length of wrench is 0.1 m.
[ since the vector
lies on y axis]
The direction of applied force is along the vector <0,2,-4>.
Then the angle between
and <0,2,-4> = the angle between F and
.
We know that,





We know that,




Here
= 100 N-m,
and 
Now




Therefore the magnitude of the force is
N.