Kate gathered 3 of the same size made of different materials: glas, clear plastic, and aluminum painted black. she placed on the window sill in the sun for an hour and then measured the warmth of the air in each box. which of the following best describes the purpose of the experiment? a)to relate the type of box material to the warmth of air within the box. b)to relate the type of box material to the mass of the box. c) to relate the amount of time a box is exposed to sunlight to the warmth of air within the box. d) to relate the size of the box to the warmth of air within the box.

Astone is dropped from a cliff and falls 9.44 meters. what is the speed of the stone when it reaches the ground? a. 13.6 m/sec b. 1.39 m/sec c. 185 m/sec d. 9.80 m/sec

What is special about a dc circuit ?

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.