A certain home electric heater uses thin metal strips to dissipate heat. The strips are 6 mm

Question:

A certain home electric heater uses thin metal strips to dissipate heat. The strips are 6 mm wide and are oriented normal to the airstream, which is produced by a small fan. The air velocity is 2 m/s, and seven 35-cm strips are employed. If the strips are heated to 870oC, estimate the total convection heat transfer to the room air at 20oC.