A forensic scientist is comparing two samples of evidence to see if they contain the same elements. Here are his findings: Sample A contains atoms which all have a mass number of 40 and an atomic number of 20. Sample B contains atoms which all have a mass number of 40 and an atomic number of 19. Which of the following conclusions is valid?

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?