How does a longer moment arm affect the force needed to lift an object?

A longer moment arm decreases the amount of force needed to lift an object due to the principles of torque. Torque is the product of the force applied and the distance from the pivot point (or fulcrum) to the point of force application. When the moment arm is extended, the torque created by a given force is increased because the distance is greater.

This means that less force is needed to achieve the same amount of torque when using a longer moment arm. In practical terms, this is why tools like levers or wrenches are effective: by increasing the length of the handle (the moment arm), one can lift or turn heavy objects with less effort. In contrast, a shorter moment arm requires a larger force to achieve similar torque, illustrating the mechanical advantage provided by longer levers.