Answer:
[tex]1311.5\ \text{Nm}[/tex]
Explanation:
l = Length of ladder = 8.57 m
m = Mass of ladder = 21.4 kg
F = Force on ladder = 258 N
[tex]\alpha[/tex] = Angular acceleration = [tex]1.63\ \text{rad/s}^2[/tex]
g = Acceleration due to gravity = [tex]9.81\ \text{m/s}^2[/tex]
Net torque is given by
[tex]\tau=lf-\dfrac{l}{2}mg\\\Rightarrow \tau=8.57\times 258-\dfrac{8.57}{2}\times 21.4\times 9.81\\\Rightarrow \tau=1311.5\ \text{Nm}[/tex]
The net torque acting on the ladder is [tex]1311.5\ \text{Nm}[/tex].