A general three-dimensional load is applied to a structure which results in a general three-dimensional stress state (left view). Using the eigenvalue approach, the three principal stresses are found to be ( σp1 = 3.3, σp2 = 8.5, σp3 = 24.9 ), (see right view), where the eigenvectors determine the orientation of (1,2,3) relative to the original (x, y,z) frame. If this element, in the principal frame (1,2,3), is rotated (45o) CCW about the positive (2-axis), then shear stresses will be produced on some or all of the three element faces. What is the magnitude of the largest of these three possible shear stresses?

Antireflective coatings on solar cells are often made by applying a thin film of silicon nitride (sinx), which has an index of refractive of 1.2, on the top of the silicon solar cell, which has a refractive index of about 3.5. however, the sun emits radiation of various wavelengths which the solar cell absorbs, and the antireflective coating can only absolutely minimize the reflection of one of these wavelengths. the coating thickness is chosen to reduce the reflection of green/yellow light (e = 2.2 ev), which is the most intense color in the solar spectrum (shown below). which of the following coatings would minimize reflection of green/yellow light? the answer is 820 nm how? what is the angular width of the central maximum of an electron traveling at 2 x 108 m/s going through a single slit of width 1 mm.