Answer:
775.48 W
Explanation:
given,
diameter of disk = 0.6 cm
length of the disk = 0.4 m
T₁ = 450 K T₂ = 450 K T₃ = 300 K
= 1.33
now,
the value of view factor (F₁₂)corresponding to 1.33
F₁₂ = 0.265
F₁₃ = 1 - 0.265 = 0.735
now,
net rate of radiation heat transfer from the disk to the environment:

= 2 F₁₃ A₁ σ (T₁⁴ - T₃⁴)
= 2 x 0.735 x π x (0.3)² x (5.67 x 10⁻⁸ W/m²) (450⁴ - 300⁴)
= 775.48 W
Net radiation heat transfer from the disks to the environment = 775.48 W
What if when I find my product, I get the same compound as I did in my
reactant? For example, FeCl3 + HCl ->FeCl3 + HCl. Then something is
wrong. In this case, FeCl3 and HCl usually don't react. In very
concentrated solutions of HCl, the FeCl4^- or FeCl6^-3 ion can form.
In... There you go my friend