Answer:
392N
Explanation:
To develop this problem it is necessary to refer to the equations based on film mechanics. In which the equations of torque and force are defined.
To develop the problem, we assume that when force F_1 is applied, the system is in equilibrium and therefore the net torque is zero.
In this way we can start from the premise that the torque on the pivot is balanced as:
[tex]F_2R_2 = mgr[/tex]
Where m is the mass of the plank and r the distance of center mass. Also [tex]R_2[/tex] represent the distance of force point [tex]F_2[/tex] from end point.
Replacing,
[tex]F_2 (50*10^{-2}) = 20(9.8)(1)[/tex]
[tex]F_2 = \frac{20*9.8*1}{50*10^{-2}}[/tex]
[tex]F_2 = 392N[/tex]
Note that I convert all the measures to International System.
