Question

why is it easier to remove an old bolt if we add an extension to the wrench handle? because there is more mass because the wrench is heavier because a higher torque is applied because a higher force is applied

Explanation:

Torque is the rotational equivalent of linear force and is calculated as the product of force and the distance from the pivot point. Adding an extension to the wrench handle increases the distance from the pivot (the bolt - head), and with the same applied force, a higher torque is generated. Higher torque makes it easier to overcome the friction and loosen the bolt.

Answer:

Because a higher torque is applied