Which statement is true of light when it speeds up on entering another medium
a) the index of refraction is higher in the second medium that it was in the first
b) the index of refraction is lower in the second medium than it was in the first
c) the speed of light though the medium is close to the speed of light in a vacuum
d) the angel of incidence equals the angle of refraction in this instance

Abeverage can is made of 3004-h19 aluminum alloy (elastic modulus 69 gpa, tensile yield strength 285 mpa, density 2.72 g/cm^3). the dimensions on the can are approximated as a thin-walled cylinder with a height of 4.83 inches, diameter of 2.60 inches. empty the can has a mass of 14.2 g. determine: a. the wall thickness of the cylinder b. assuming a pinned-pinned condition what is the critical load? c. assuming a fixed-fixed condition what is the critical load?