Convert from barn to tunnland

Unit Definition (barn)
The Barn is a slightly humorous unit of area used in nuclear physics. When atoms are bombarded with smaller particles such as electrons, the electrons are scattered as if the nucleus of the atom was a tiny solid object. The barn is used to express the apparent cross-sectional area of this scattering object. One barn is equal to 1E-28 square meters. Using this unit, physicists can say that such and such a nucleus is "as big as a barn", or 10 barns, or whatever. The proper SI unit to use for these measurements is the square femtometer (fm²); one barn equals 100 fm².

Unit Definition (tunnland)
The tunnland is a traditional unit of land area in Sweden. The tunnland is equal to 56 000 square Stockholm feet (kvadratfot); this is equivalent to 4936.4 square meters, 0.493 64 hectare, or about 1.220 English acre. The tunnland was divided into 32 kappland. Like the Danish tønde land (see above), this unit originated as the area that could be planted with one tunn (barrel) of seed.