Answer:
Q = 424523.22 kw
Step-by-step explanation:

k = 48.9 W/m - K
c = 0.115 KJ/kg- K


T_∞ = 35 degree celcius
velocity of air stream = 15 m/s
D = 40 cm
L = 200 cm
mass flow rate




solving for h

h = 675.6 kw/m^2K

Q = 675.6*2.513*(285-35)
Q = 424523.22 kw