Two ice skaters, daniel (mass 70.0 kg ) and rebecca (mass 45.0 kg ), are practicing. daniel stops to tie his shoelace and, while at rest, is struck by rebecca, who is moving at 12.0 m/s before she collides with him. after the collision, rebecca has a velocity of magnitude 7.00 m/s at an angle of 52.1 ? from her initial direction. both skaters move on the frictionless, horizontal surface of the rink.

a what is the magnitude of daniel's velocity after the collision?

b what is the direction of daniel's velocity after the collision?

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.