As demonstrated by the doppler effect, why does sound increase in pitch as a sound source approaches you?
a. object vibrates slower when they move forward
b. the wave is farther apart because the object is moving toward you
c. objects vibrate faster when they move forward
d. the waves are closer together because object is moving towards you

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?