# Conversions/Significant Figures/Graphing/Measurements

```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
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
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
```