In a “minute to win it” game, cards are placed between cups to stack them. The contestant then pulls the card out in hopes that they will end with a set of stacked cups. Why does this work?

There is no friction between the card and the cup.

Inertia will keep the top cup from moving very far. Gravity will pull one cup on top of another.

The opening of the cup is so much bigger than the bottom, even though the cup moves they will both be stacked together.

Both cups are moved the same amount by the friction between them and the card.

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.