A tile-iron consists of a massive plate maintained at 150 degrees Celsius 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 i heated above 50 degrees celsius for at least 2 minutes, but its temperature should not exceed 120 degrees Celsius. Assume the tile and subfloor to have an initial temperature of 25 degrees Celsius and to have equivalent thermophysical properties of k = .15 W/mK and (rho*c_p) = 1.5 * 10 ^ J/m^3K.
a) How long will it take a worker using the tile-iron to lift a tile? Will the adhesive temperature exceed 120 degrees C?
b) If the tile-iron has a square surface area 254mm to the side, how much energy has been removed from it during the time it has taken to lift the tile?