(4 points) A mother with mass m1 is skating at velocity v1 behind her daughter whose mass is m2, who is skating at v2 . Instead of passing her, Mother inadvertently crashes into Daughter and grabs Daughter around the waist. They maintain their balance and skate off together with velocity vf , right after the collision. a) Sketch the problem with before-and-after diagrams. (You can represent the skaters as blocks). b) Is the collision best described as elastic, inelastic, or perfectly inelastic, why? c) Write the general equations for conservation of momentum in terms of m1 , m2 , v1, v2 , and final velocity vf . d) Given: m1 = 70.0 kg, v1 = 8.00 m/s m2 = 50 kg, v2= 4.00 m/s Solve for the final velocity vf . e) If the collision last 0.25 s, what is the average force delivered during the collision?

What is the order of the moon, earth, and sun in a lunar eclipse and a solar eclipse?

What is required for an electric charge to flow through a wire? zero resistance in the wire a balance of electric potential high resistance in the wire a difference in electric potential

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.