What mass of a material with density Ï is required to make a hollow spherical shell having inner radius r1 and outer radius r2? (use any variable or symbol stated above as necessary.) ?

Who is galileo galilei

18. In an airplane flying at a constant speed, the force pushing the airplane forward is exerted by the engine and is equal to the opposite force of air resistance. Describe how these forces compare when the plane speeds up and slows down.

A technician places a fluid substance, with a refractive index of 1.61, between two horizontal panes of flat glass (each of which has n = 1.45). She then illuminates the assembly from above with monochromatic light (λ = 330 nm).

Which detail best explains how Esperanza is changing?

Radial tires generally give the best gas mileage. a. true b. false

Trace fossils are recognized as evidence of which pre-existing life? plants plants and animals neither plants nor animals animals

A net force of 30 N is applied to an object with a mass of 15 kg. The object accelerates at 2 m/s2. If half the force is applied, what happens to the acceleration?

A 770 n man stands in the middle of a frozen pond of radius 10.0 m. he is unable to get to the other side because of a lack of friction between his shoes and the ice. to overcome this difficulty, he throws his 1.

Which equation represents the total energy of a system?

The weight of a 100 N laser printer is spread over 0.5m2. What is the pressure it exerts? A) 50 N/m2 B) 200 N/m2 C) 500 N/m2