Prove that for all integers a and b, if a mod 7 = 5 and b

Conceptual Physics 12
Problem 9E If Earth were smaller than it is, but the Alexandria-to-Syene distance were the same, would the shadow of the vertical pillar in Alexandria be longer or shorter at noon during the summer solstice?

Fluid Mechanics 2
Problem 64P What is viscosity? What is the cause of it in liquids and in gases? Do liquids or gases have higher dynamic viscosities?

An Introduction to Thermal Physics 1
Problem 35P According to the Sackur-Tetrode equation, the entropy of a monatomic ideal gas can become negative when its temperature (and hence its energy) is sufficiently low. Of course this is absurd, so the Sackur-Tetrode equation must be invalid at very low temperatures. Suppose you start with a s

Fundamentals of Statistics 4
Problem 18AYU Problem You Explain It! Quartiles One variable that is measured by online homework systems is the amount of time a student spends on homework for each section of the text. The following is a summary of the number of minutes a student spends for each section of the text for the fall 20

Statistics Through Applications 2
Radio station call signs, II Refer to Exercise 8.39. By 1922, there were more applications for radio station licenses than the number of three-letter call signs available. A radio station in New Orleans applied for and was granted the call sign WAAB. (a) How many four-letter call signs start with the

Campbell Biology 9
Which of the following processes includes all others? a. osmosis b. diffusion of a solute across a membrane c. facilitated diffusion d. passive transport e. transport of an ion down its electrochemical gradient

Krugman's Economics for AP® (High School) 2
Which kind of profit is just enough to keep a firm operating in the long run? a. normal b. economic c. accounting d. implicit e. explicit

Organic Chemistry 8
Identify the most electronegative element in each of the following molecules: (a) CH2FCl (b) FCH2CH2CH2Br (c) HOCH2CH2NH2 (d) CH3OCH2Li