Chapter 9, Problem 19PE

What is the mechanical advantage of a nail puller similar to the one shown in Figure 9.23 —where you exert a force 45 cm from the pivot and the nail is 1.8 cm on the other side? What minimum force must you exert to apply a force of 1250 N to the nail?

Figure 9.23 A nail puller is a lever with a large mechanical advantage. The external forces on the nail puller are represented by solid arrows. The force that the nail puller applies to the nail ( F_o ) is not a force on the nail puller. The reaction force the nail exerts back on the puller ( F_n ) is an external force and is equal and opposite to F_o. The perpendicular lever arms of the input and output forces are l_i and l₀