4-2. The uniform internal energy u"" is generated in a 2L x 21 x 8 rectangular flat plate (Fig. 4-43). The upward and downward heat transfer coefficients are hi and h2, respectively. The peripheral heat transfer coefficient is large. The ambient temperature is T. Find the steady temperature of the plate. T -2L- 21 h₂ FIG. 4-43 =∞ PROBLEMS