solve 17.24 please

17.23 Liquid nitrogen at 77K is stored in an insulated spherical container that is vented to the atmosphere. The container is made of a thin-walled material with an outside diameter of 0.5m;25mm of insulation (k=0.002W/mK) covers its outside surface. The latent heat of nitrogen is 200 kJ/kg; its density, in the liquid phase, is 804kg/m3. For surroundings at 25C and with a convective coefficient of 18W/m2K at the outside surface of the insulation, what will be the rate of liquid nitrogen boil-off? 17.24 What additional thickness of insulation will be necessary to reduce the boil-off rate of liquid nitrogen to one-half of the rate corresponding to Problem 17.23? All values and dimensions in Problem 17.23 apoly