20.1-6. drying of wood. a flat slab of douglas fir wood 50.8 mm thick and containing 30 wt % moisture is being dried from both sides (neglecting ends and edges). the equilibrium moisture content at the surface of the wood due to the drying air blown over it is held at 5 wt % moisture. the drying can be assumed to be represented by a diffusivity of 3.72 × 10 –6 m2 /h. calculate the time for the center to reach 10% moisture.

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?

Assuming compressible flow of air and that the measurements are done at flagstaff a pitot static tube that gives the difference of total and static pressure measures 0.35 m of mercury. what is the velocity of air? assume the temperature to be 300k. (submit your excel or matlab calculation sheet)

Which one from below is not one of the reasons of planning failures? (clo3) a)-planner is careless. b-planner spend less time in the field but more time on the desk c)-planner is not qualified d)-planner does not have sufficient time to properly plan