A 3000kg roller coaster tops a 65m hill with a speed of 3m/s. It then rolls down to a dip 10m off the ground and climbs up to a small hill 20m above the ground. What is its KE and speed at the end?

The velocity of a curling stone is due east. what will be the direction of the momentum of the curling stone as it moves?

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 frequency of the fundamental of the guitar string is 320 hz. at what speed v do waves move along that string?