Exposed ceiling beams are popular in many modern houses. however, because they are exposed, their ignition in the event of a fire is of concern. consider a 15 cm by 15 cm yellow pine beam, initially at 25°c, attached to a ceiling, thus insulat- ing the base. the three other sides are exposed to fire at 600°c with a combined convective/radiative heat transfer coefficient of 50 w/m2.k. determine the beam's maximum temperature 5 min after fire starts.