Q.5 The experimental average diffusion coefficient of moisture in a given paper is 2.97 x 10-6 m/hr. Large planks of paper measuring 15.15 X 14.8 X 2.54 cm thick are dried from both sides by air having relative humidity of 40 %. The air temperature is 100 C. Calculate the time needed to dry paper from initial moisture content of 29 % to 15 % and comment on the accuracy of the time