Hi there!
Recall the equation for Torque:
[tex]\large\boxed{\Sigma \tau = rFsin\phi}[/tex]
In words, the torque is the force multiplied by the distance from the LINE OF ACTION to the PIVOT POINT.
In this instance:
F = Mg = 0.75 · 9.8 = 7.35 N
r = 1.25 m
sin(30) = 0.5
Plug in the values:
[tex]\Sigma \tau = (1.25)(7.35)(0.5) = \boxed{4.59 Nm}[/tex]
