Hydrogen flows through a horizontal insulated duct. At section1 the enthalpy is 2400 btu/lbm, the density is .5 lbm/ft^3 and the velocity is 500 ft/sec. at at downstream section, h2= 2240 btu/lbm and density2= .1 lbm/ft^3. No shaft work is done. Determine the velocity at section 2 and the ratio of areas.