A mechanic wants to unscrew some bolts. She has two wrenches available: one is 35 cm long, and one is 50 cm long. Which wrench makes her job easier and why?
the longer the lever arm, the smaller the force.
To determine which wrench makes the mechanic's job easier, we need to consider the concept of torque. Torque is the measure of the force required to rotate an object around an axis.
Torque is calculated by multiplying the force applied and the distance from the axis of rotation. In this case, the axis of rotation is the point where the wrench is applied to the bolt, and the force is the mechanic's effort to turn the bolt.
Since the mechanic wants to unscrew the bolts, she needs to apply a sufficiently large torque to overcome the resistance and turn the bolts. The longer the wrench, the more torque she can generate for a given force applied.
The torque is directly proportional to the length of the wrench, assuming the same force is applied. Therefore, the longer wrench, which is 50 cm in this case, will make the mechanic's job easier. It allows her to generate more torque than the shorter wrench, making it easier to loosen tight bolts.