Question

An old carpenter’s trick to keep nails from bending when they are pounded into hard materials is to grip the center of the nail firmly with pliers. Why does this help?

a) Decreases friction between nail and material.
b) Increases the force applied to the nail.
c) Distributes force evenly on the nail.
d) Reduces the moment of force on the nail.

Answer 1

Using pliers to grip the center of a nail while hammering into a hard material is an effective trick because it reduces the moment of force on the nail, which decreases the likelihood of the nail bending.

Step-by-step explanation:

Gripping the center of a nail with pliers provides a professional carpentry tip to prevent the nail from bending while being hammered into hard materials. This works because it reduces the moment of force on the nail. When the force of the hammer is applied to the nail, the presence of the pliers changes the nail's effective length, thus reducing the lever arm and the moment (torque) that can cause the nail to bend. By shortening the distance from the point of force application (the hammer hit) relative to the pivot point (where the nail encounters resistance from the hard material), there is less chance for the nail to deflect and bend.

Therefore, the correct answer is (d) Reduces the moment of force on the nail.