Heat from a flat wall is to be enhanced by adding straight fins, of constant thickness, made of stainless steel. The following specifications apply:

h                                              = 60 W/m² K

T_b (base)                                 = 120°C

T_∞ (air)                                     = 20°C

Fin base thickness, t             = 6 mm

Fin length, L                           = 20 mm

Determine the fin efficiency and heat loss per unit width for the finned surface.