To remove a nail from wood, a lever will be the best machine to use. In a lever, effort is applied to move a large load. The nail is treated as the load.
Most hammers have nail removers that can be used to pull out nails.
The force is applied at the handle.
The head of the hammer has a fulcrum and nail remover part where the load is.
This gives a large mechanical advantage and the nail can be pulled out.
Wedge, wheel and axle and movable pulley are not machines that works as nail removers.
