Vocabulary Words Week 3 accuracy precision percent Error graph significant Figure asseverate bastion esoteric indubitable coterie

Quiz Review Quiz Wednesday Base Units & Derived Units –Examples of each Accuracy & Precision Temperature Scales –K = °C Percent Error Metric Conversions Density –Liters of water to grams of water –D= M/V –V= M/D –M= D*V

Scientific Notation Convenient way of writing very small or large numbers Consists of two parts –Number & ten raised to an exponent Exponent is negative, number will be smaller than 1 Exponent is positive, number will be bigger than x ,392,412, x 10 11

1.47, x x x x x x x x 10 -4

Scientific Notation Adding and Subtracting –Exponents MUST BE THE SAME before doing the math! –Add the numbers and rewrite x10 exponent (2.7*10 7 ) + (1.56*10 5 ) (270*10 5 ) +(1.56*10 5 ) = *10 5 = 2.7 * 10 7 (8.3*10 8 ) – (4.1*10 6 ) (830*10 6 ) – (4.1*10 6 ) = *10 6 = 8.3 *10 8

x10 5 – 2.8 x x x10 3

Scientific Notation Multiplying 1)Multiply the first factors 2)Add the exponents (2*10 3 ) * (3*10 3 ) = 6*10 6 (4*10 6 ) * (2*10 -4 ) = 8*10 2 Dividing 1)Divide the first factors 2)Subtract the exponents (6*10 4 ) ÷ (3*10 2 ) = 2*10 2 (9*10 3 ) ÷ (3*10 -4 ) = 3*10 7 (3- (-4)) = 3+4

x10 -4 / 4.1 x x10 -2 / 2.4 x x10 -4 / 4.8 x x10 3 x 5.2 x x 10 6 x 6.76 x x 10 3 x 9.8 x 10 -4

Significant Figures Scientists indicate the precision of measurement by the numbers of digits they report –4.2 gnot precise – gvery precise Significant digits include all known digits plus one estimated digit

Sig Fig Rules (pg.39) 1.Any non-zero digits are always significant 2.Any zeros between 2 significant digits are significant 3.Any zeros to the right of the decimal AND on the end of the number * , * , 000,

Sig Figs Adding and Subtracting –Answer must have same # of digits to the right of decimal as the value w/ the fewest digits to the right of decimal (4.32*10 3 ) – (1.6*10 3 ) = 2.72*10 3 = 2.7 * = 77.2

Sig Figs Multiplying and Dividing –Answer must have same number of significant figures as the measurement with the fewest significant figures 3.20 * 3.65 * 2.05 = = * 3.26 = = * 0.10 = = ÷ 2.4 = = ÷ 58 = = 2.9

Graphs Visual display of data

Setting up the Graph Adjust your scale to ensure the graph occupies the most space Your values need to increase at a steady rate (for example count by 2)

Setting up the graph… X axis –Always on horizontal axis –Always independent variable Y axis –Always on vertical axis –Always dependent variable

Which is dependent variable? Amount of fertilizer Growth rate of plants Number of years Increase in population Inches of rain that fell Month rainfall occurred Amount due on cell phone bill Minutes used

Interpolation Finding an unknown point between 2 measured points A B C

Extrapolation Finding an unknown point that is outside of 2 measured points A B C

Best fit line Straight line that averages the data points