Q A in VS .NET

Maker EAN / UCC - 13 in VS .NET Q A

Calculate the percent error in the officer s measurement of the Ferrari s speed 315% First, divide the absolute value (the size, as a positive number) of the error by the actual value: | 4 mph| / 127 mph = 4 mph / 127 mph = 00315 Next, multiply the result by 100 to obtain the percent error: Percent error = 00315 100 = 315%

Two people, Reginald and Dagmar, measure their weight in the morning by using typical bathroom scales, instruments that are famously unreliable The scale reports that Reginald weighs 237 pounds, though he actually weighs 256 pounds Dagmar s scale reports her weight as 117 pounds, though she really weighs 129 pounds Whose measurement incurred the greater error Whose incurred a greater percent error

Two jewelers were asked to measure the mass of a gold nugget The true mass of the nugget was 0856 grams (g) Each jeweler took three measurements The average of the three measurements was reported as the official measurement with the following results: Jeweler A: 0863g, 0869g, 0859g Jeweler B: 0875g, 0834g, 0858g Which jeweler s official measurement was more accurate Which jeweler s measurements were more precise In each case, what was the error and percent error in the official measurement

After you know how to express your numbers in scientific notation and how to distinguish precision from accuracy (we cover both topics earlier in this chapter), you can bask in the glory of a new skill: using scientific notation to express precision The beauty of this system is that simply by looking at a measurement, you know just how precise that measurement is When you report a measurement, you should only include digits if you re really confident about their values Including added digits in a measurement means something it means that you really know what you re talking about so we call the included digits significant figures The more significant figures in a measurement, the more precise that measurement must be The last significant figure in a measurement is the only figure that includes any uncertainty Here are the rules for deciding what is and what isn t a significant figure: Any nonzero digit is significant So, 642 seconds (s) contains three significant figures Zeros sandwiched between nonzero digits are significant So, 307s contains three significant figures Zeros on the left side of the first nonzero digit are not significant So, 00642s and 000307s each contain three significant figures When a number is greater than 1, all digits to the right of the decimal point are understood to be significant So, 176s has three significant figures, while 1760s has four significant figures The 6 is uncertain in the first measurement, but is certain in the second measurement

When a number has no decimal point, any zeros after the last nonzero digit may or may not be significant So, in a measurement reported as 1,370s, you can t be certain if the 0 is a certain value, or if it s merely a placeholder Be a good chemist Report your measurements in scientific notation to avoid such annoying ambiguities (see the earlier section, Using Exponential and Scientific Notation to Report Measurements ) Numbers from counting (for example, 1 kangaroo, 2 kangaroos, 3 kangaroos ) or from defined quantities (that is to say, 60 seconds per 1 minute) are understood to have an unlimited number of significant figures; in other words, these values are completely certain If a number is already written in scientific notation, then all the digits in the coefficient are significant, and none others So, the number of significant figures you use in a reported measurement should be consistent with your certainty about that measurement If you know your speedometer is routinely off by 5 miles per hour, then you have no business protesting to a policeman that you were only going 632 miles per hour

How many significant figures are in the following three measurements 20,175 yards, 175 105 yards, 1750 105 yards

A 15

Five, three, and four significant figures, respectively In the first measurement,

all digits are nonzero, except for a 0 that is sandwiched between nonzero digits, which counts as significant The second measurement contains only nonzero digits The third measurement contains a 0, but that 0 is the final digit and to the right of the decimal point, and is therefore significant

Modify the following three measurements so that each possesses the indicated number of significant figures (SF) and is expressed properly in scientific notation 7693 10 2 meters (1 SF), 00007693 meters (2 SF), 7693 meters (3 SF)