How much force does it take to pull out a penny nail from wood common wood?

The force required to pull out a penny nail from common wood varies based on factors such as the type of wood, the nail's length and diameter, and how well the nail is embedded. Generally, it can take anywhere from 5 to 20 pounds of force to extract a penny nail from softwoods like pine, while hardwoods may require more force due to tighter grain structure and increased friction. For precise measurements, a tensile testing machine would provide accurate values under controlled conditions.