Answer:
[tex]F' = 4F[/tex]
Explanation:
When force applied to the end of the rod in perpendicular direction then net torque on the rod is given as
[tex]\tau = L F sin90[/tex]
[tex]\tau = LF[/tex]
Now another force is applied at mid point of the rod at an angle of 30 degree with the rod
so new value of torque is given as
[tex]\tau = \frac{L}{2}F' sin\theta[/tex]
[tex]LF = \frac{L}{2}F' sin30[/tex]
[tex]LF = \frac{F'L}{4}[/tex]
so we have
[tex]F' = 4F[/tex]