Describe the mechanism of crack propagation for both ductile and brittle fracture modes. Explain in your own words why the Griffith criterion for fracture, which worked exceedingly well for glass, had to be modified by Orowan to accommodate the behavior of metals.

You are making beer. the first step is filling the glass carboy with the liquid wort. the internal diameter of the carboy is 15 in., and you wish to fill it up to a depth of 2 ft. if your wort is drawn from the kettle using a siphon process that flows at 3 gpm, how long will it take to fill?