What must exist for the engineering process to begin? a. a problem
ь. a solution
c. research
d. scientific tools

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.

What is the measure of how much matter is in an object and that can be measured using a balance? a. height b. volume c. weight d. mass

During cooling, the kinetic energy of the molecules falls. why does this happen? a. the motion of the molecules increases. b. the motion of the molecules slows down. c. the van der waals forces between molecules decrease d. the forces of attraction between the molecules are overcome.