Ethan is using a machine to mix cement. the work input is 10 and the work output is 8. what is the efficiency of the machine?

You've already seen the value of 9.8 in this lesson. what's this value called? what quantity does it represent?

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.

The three classes of rocks are sedimentary, metamorphic, and igneous. how are rocks classified into one of these three groups?