3) A spherical tank, 1m in diameter, is maintained at a temperature of 120C and exposed to a convection environment. With h=25W/m2+C and T=15C, what thickness of urethane foam should be added to ensure that the outer temperature of the insulation does not exceed 40C ? What percentage reduction in heat loss results from installing this insulation? 3) A spherical tank, 1m in diameter, is maintained at a temperature of 120C and exposed to a convection environment. With h=25W/m2+C and T=15C, what thickness of urethane foam should be added to ensure that the outer temperature of the insulation does not exceed 40C ? What percentage reduction in heat loss results from installing this insulation