A tile-iron consists of a massive plate maintained at 150°C by an embedded electrical heater. The iron is placed in contact with a tile to soften the adhesive, allowing the tile to be easily lifted from the subflooring. The adhesive will soften sufficiently if heat above 50°C for at least 2min, but its temperature should not exceed 120°C to avoid deterioration of the adhesive. Assume the tile and
subfloor have an initial temperature of 25°C and to have the same thermo-physical properties copper (ρcv = 1.5x106J/m3K; k = 0.15W/mK).
a) How long will it take a worker using the tile-iron to lift a tile?
b) Will the adhesive temperature exceed 120°C?
thikness 4 mm