advertisement

Conversions/Significant Figures/Graphing/Measurements Walking 25 distance (meters) 20 15 Series1 10 5 0 0 1 2 3 4 5 6 time (seconds) Graphing First, draw a best fit line as close to as many points as possible using a straight edge. Then use that line to answer the questions below about the line you drew. Slope = ______________ Units for slope ________________ y-intercept = ________________ Units for intercept______________ How many sig figs should you include?___________________Fix your answers to reflect the correct #. 1) What does the slope of this graph tell us about walking (hint: think about the units)? 2) What does the y-intercept of this graph tell us (hint: think about the units)? 3) Explain how two excellent students working on this same graph could get two different answers for the slope (neither made mistakes). Using the ruler below, report the length of the bold line with a range of uncertainty with units and the right number of sig figs. llllllllllllllllllllllllllllllllllllll 0 1 2 3cm Line is ___________________ In lab, Sally measured a block to be 2.34 +/- 0.03m but Harold measured the same block as 2.38 +/- 0.03m. Which measurement is correct? Explain. On a test you scored 3 wrong out of 50 questions. What percent did you get wrong?_______________ Range of uncertainty reports how “wrong” a measurement is. Using the same method as the percent wrong above, calculate the percent uncertainty if you report a measurement as 2.34 +/- 0.03m _____________ Physics Significant Figures/Graphing (salmon) edited2/9/16 How many significant figures do the following numbers have? 4) 3.467 5) 4.0980 6) 509.0 7) 3900 8) 50089 9) 200. 10) 0.0090 ________________ ________________ ________________ ________________ ________________ ________________ ________________ Calculate to the correct number of significant figures. 11) 5.908 x 400 = ________________ 12) 3.6 x 444 = ________________ 13) 5.99/ 0.06 = ________________ 14) (3.5060 x 90.0)/33 ________________ 15) 200 + 13.90 ________________ 16) 0.97 – 0.034 ________________ 17) 7840.9 + 0.12 ________________ What can you tell me about the difference in the quality of these two measurements? 3.456 And 3.45678 Why do scientists have to use significant figures? Convert the following and use significant figures. Note: We assume conversion factors are infinitely correct therefore they do not limit, or change, the number of sig figs in an answer. 18) 24.7cm = ________________mm 19) 6.576 kg = ________________mg 20) 15.3 inches = _____________cm 21) 20.km/hr = ________________m/s 22) 40.miles/hr = ________________m/s Physics Significant Figures/Graphing (salmon) edited2/9/16