1. Suppose that a researcher wanted to see if there was a significant difference between freshmen in college who attended orientation and those who do not attend and the effect it has on the first semester grade point average. What type of design could the researcher develop to conduct this study? What would be some threats to internal validity?

Hydrogen and helium are both members of?

How do we measure or think of speed in the united states?

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.