Two football players are running toward each other. one football player has a mass of 105 kg and is running at 8.6 m/s. the other player has a mass of 90 kg and is running at –9.0 m/s.
the momentum of the system after the football players collide is kg • m/s.

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative

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.

Match each scenario to the form of energy it represents