The following questions are from the group work during the week of 12/7 to
12/11. Include worked out solutions for each
problem. These may be screenshots from
your PearDeck, but must be your own work
(you have to write it out, you can’t just
submit someone else’s screenshot)

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.

Greg drew a diagram to compare two of the fundamental forces. which labels belong in the areas marked x, y and z? gravitational force electromagnetic force x. attractive y repulsive z: infinite range x: infinite range y attractive z. repulsive x. always attractive y: infinite range z: attractive or repulsive x. attractive or repulsive y infinite range z: always attractive

The radius of a sphere is increasing at a rate of 9 cm/ sec. find the radius of the sphere when the volume and the radius of the sphere are increasing at the same numerical rate.