Answer:
A force of 75 N placed at 0.7 m on the meter stick.
Explanation:
The weight of the box is equal to:
[tex]W=mg=3*10=30N[/tex]
The net torque is equal to zero and is equal to:
[tex]F(x-0.5)-(30*0.5)=0\\F(x-0.5)=15[/tex]
For a force with a value of 75 N that is placed at 0.70 m on the meter stick, it would produce a torque of 15 N m
If you replace that values in the equation:
[tex]75(0.7-0.5)=15\\15=15[/tex]