Given,
The horizontal force applied, F=125 N
The angle made by the nail, θ=26°
Distance from the pivot point to point at which the force F is applied, D=28 cm= 28×10⁻² m
The distance from the pivot point to the nail, d=5.86 cm=5.86×10⁻² m
The horizontal force, F, applied to the hammer will give a certain torque to the hammer. Which will transfer the force to the nail.
Thus the torque due to the applied force F will be equal to the torque applied by the hammer to the nail.
Therefore,

Where f is the force that the hammer exerts on the nail.
On substituting the known values,

Thus the force exerted by the hammer on the nail is 1362.47 N