As shown in figure, an N-turn electromagnet is to be used

As shown in figure, an N-turn electromagnet is to be used to lift a slab of iron of mass M. The surface roughness of the iron is such that when the iron and the electromagnet are in contact, there is a minimum air gap of g min = 0.18 mm in each leg. The electromagnet cross-sectional area Ac = 32 cm and coil resistance is 2.8 ?. Calculate the minimum coil voltage which must be used to lift a slab of mass 95 kg against the force of gravity. Neglect the reluctance of the iron.