A thermometer reads 50C at a steady-state. At time t= 0. the thermometer is placed in a water bath maintained at 80C. Determine the time needed (in seconds) for the thermometer to read 60C. Data: Cylindrical bulb of a typical laboratory thermometer is 3 mm in diameter and 12 mm long Density of mercury = 13600 kg/m? Density of hot water = 1000 kg/m3 Specific heat of mercury = 0.033 kcal/kg C. Specific heat of water = 1 kcal/kg C. Heat transfer coefficient of still water = 7.5 kcalmin m2 C. Heat transfer coefficient of air = 0.5 kcal min m2 C. Formula to calculate volume of bulb is trh and area of the bulb is 2nr(h+r)