Quenching is a rapid cooling process by which many metallic alloys are hardened. Brass (a copper alloy: 70 Cu, 30 Zn) plates that are 4 mm thick are quenched in a water bath at a heat treating plant. If a brass plate is initially at 450°C, determine the quench time needed for the plate to attain 90°C. The water bath temperature is 80°C and has an average convective heat transfer coefficient of 2500 W/m² •K. Also, if the rectangular plate is 1 m wide and 2 m long, determine the total amount of heat imparted to the bath during quenching.