Imagine a glass box that is completely sealed and in that box is a cactus in a small pot. which statement is most accurate?
a. this is a closed system because light enters through the glass box.
b. this is an open system because light can go through the glass and get into the box.
c. this is a closed system because nothing of substances gets in our out of the box.
d. this is an open system because air is circulating inside the glass box.

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.