2. An airplane weighing 73.6 kN has elliptic wings 15.23 m in span with no geometric twist and a planform area of 19.8 m2 . For a speed of 90 m/s in steady, level flight at sea level ( = 1.2256 kg/m3 ) calculate the value of the circulation in the plane of symmetry (o), the downwash velocity, w, the induced drag, D, i, the geometric angle of attack, , and the effective angle of attack, eff. Assume that L=0 = -1.2°.

Alinearly polarized electromagnetic wave has an average intensity of 196 w/m^2. this wave is directed towards two ideal polarizers (in real polarizers, transmission is also effected by reflection and absorption). polarizer a is oriented with its transmission axis at an angle of θ_1=20.8∘ with the incident electric field. polarizer b has its axis at an angle of θ_2=63.0∘ with the incident electric field. what is the average intensity of the wave after it passes through polarizer a? what is the average intensity of the wave after it passes through polarizer b? suppose that the two polarizers a and b are interchanged. what would the average intensity be after passing through both polarizers?

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.

Select all the correct answers. which three statements about electromagnetic radiation are true?