Consider two 2-cm-thick large steel plates (k = 43 W/m · °C and α = 1.17 × 10-5 m2/s) that...

Consider two 2-cm-thick large steel plates (k = 43 W/m · °C and α = 1.17 × 10-5 m2/s) that were put on top of each other while wet and left outside during a cold winter night at -15°C. The next day, a worker needs one of the plates, but the plates are stuck together because the freezing of the water between the two plates has bonded them together. In an effort to melt the ice between the plates and separate them, the worker takes a large hair dryer and blows hot air at 50°C all over the exposed surface of the plate on the top. The convection heat transfer coefficient at the top surface is estimated to be 40 W/m2 · °C. Determine how long the worker must keep blowing hot air before the two plates separate.