Answer: It decreases.
Explanation:
Lever arm is defined as the "perpendicular distance that exists from the rotation axis to the line of action of the force". Being its magnitude [tex](Nm)[/tex] related to the application of the force that produces a torque.
To understand it better:
The lever arm is an effective distance to apply a force with respect to a certain point, and this distance serves as an effective applied force amplification factor.
In this sense, Torque [tex]\tau[/tex] is defined as:
[tex]\tau=rFsin \theta[/tex]
Where:
[tex]r[/tex] is the distance from the applied force to the fulcrum
[tex]F[/tex] is the applied force
[tex]\theta[/tex] is the angle between [tex]r[/tex] and [tex]F[/tex]
It is important to note, [tex]\tau[/tex] is maximum when [tex]\theta=90\°[/tex]. Then, assuming [tex]r[/tex] and [tex]F[/tex] remains the same, if [tex]\theta[/tex] decreases [tex]\tau[/tex] decreases, as well.
Hence:
If the angle [tex]\theta[/tex] decreases, the magnitude of the lever arm will decrease.
So, the greater the lever arm, the greater the torque and the lesser the force we have to apply.
