Applying a force on a hammer to a nail involves an amount of force to be applied on the hammer, since it is a first class order lever that requires effort to be applied so as to function.
Thus with respect to Newton's third law of motion which states that: action and reaction forces have the same value but acts in contrary directions. Then the amount of force applied to the hammer will also be 10 N.
So that the amount of force exerted on nail is the same as the force applied on hammer.
