σV= ([(∂v/∂m).( σm)]2 + [(∂v/∂δ). (σδ)]2 )1/2
σV = ((-m/δ2).σδ)2 + ((1/ δ).σm)2=
σV = [((-46,82/2,702).0,001)2+((1/2,70).0,01)2]1/2= 7,41.10-3
V= (17,34±0,01) cm