Buildings of various constructions exhibit different responses to thermal changes in climate conditions. Consider a 10-cm-thick wall of normal weight structural concrete (c = 0.9 kJ/kg · ºC) suddenly exposed to a "blue norther" at−10ºCwith a convection coefficient of 65 W/m2 · ºC. The wall is initially at 15ºC. Estimate the time required for the wall temperature to drop to 5ºC. State the assumptions.