Answer:
The value is  [tex]W = 450 \ N[/tex]   Â
Explanation:
From the question we are told that
  The force applied at the other end is  [tex]F = 350 \ N[/tex]
  The length of the lever is  [tex]l = 3.2 \ m[/tex]
   The distance from the fulcrum to  the underside of a boulder is [tex]x_1 = 1.4 \ m[/tex]
   The distance from the fulcrum to the point where the farmer applied the force is Â
     [tex]x_2 = 3.2 - 1.4[/tex]
=> Â Â Â Â [tex]x_2 = 1.8 \ m[/tex]
Generally at equilibrium the net torque experienced by the lever is  0 and this is mathematically represented as
      [tex]F * x_2 - W * x_1 = 0[/tex]
Here W is the maximum force applied to the boulder by the lever
So
      [tex]F * x_2 - W * x_1 = 0[/tex]
=> Â Â Â [tex]350 * 1.8- W * 1.4 = 0[/tex]
=> Â Â Â Â [tex]W = 450 \ N[/tex] Â Â Â
