Consider the one-dimensional wall shown in the sketch, which is initially at a uniform temperature ti and is suddenly subjected to the convection boundary condition with a fluid at t[infinity]. for a particular wall, case 1, the temperature at x = l1 after t1 = 100 s is t1(l1, t1) = 315°c. another wall, case 2, has different thickness and thermal conditions as shown. case l (m) α (m2/s) k (w/m · k) ti (°c) t[infinity] (°c) h (w/m2 · k) 1 0.10 15 × 10−6 50 300 400 200 2 0.40 25 × 10−6 100 30 20 100 how long will it take for the second wall to reach 28.5°c at the position x = l2? use as the basis for analysis, the dimensionless functional dependence for the transient temperature distribution expressed in equation 5.41.