ib graphing. usually give graphical data display because: see relationship btw variables...
TRANSCRIPT
Usually give graphical data display because:
• See relationship btw variables (increasing, decreasing or none).
• See outliers from data.• Determine function.• Finding physical
constants from slope and intercepts.
Error Bars
• When measurement expressed with absolute uncertainty - graph with error bars. Bars show absolute uncertainty in individual measures.
• Error bar is sketched as vertical and horizontal lines beginning at data point ending in horizontal line or cap.
• Bar length is scaled to the graph axis.
• Line or curve must touch some portion of bar.
Some error bars are different lengths why?
Different instruments
Calculated deviation from mean for each.
How to graph by hand• Label Graph axes with units.• Scale – large take up most of page.• Plot dots w/bars.• Line or curve of best fit by hand or with ruler. Should
touch error bars.• Best fit straight line may or may not pass through
origin.• Transform/Linearize curves.• Calculate slope & slope uncertainty for linearized
graph. Those are physical constants.• Slope points – far apart and shown on line.• Intercepts are constants (or offset errors).
Graph Analysis
• Linear Proportion y = mx + b• Test: y/x = k any 2 points
2.4 3.2 4 4.8 5.6 6.4 7.2 8 8.8 9.60
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Stretch
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Inverse hyperbolic
• Y = k/x test: yx = k• Transform/linearize graph by plotting y
against 1/x to get linear.
Parabolic
• Y = kx2. y/x2 = k• Or transform graph y against x2 make it linear• What will the slope be?
What graph is this?
• Square root function.• Y = k • How would we linearize it?• Graph instead of x.
Hooke’s Law dataMake graph with error bars
Force ± 5 N 100 150 200 250 300
Stretch ± 0.2 cm 3.0 4.4 6.2 7.5 9.1
• Bozeman – Beginners to Graphing 10 min.• http://www.youtube.com/watch?v=9BkbYeTC6Mo&list=PLllV
waZQkS2omBpLjQm_BAQKsQ7lq86ku&index=4
• Bozeman Graphing by hand instructions 6 min.• http://www.youtube.com/watch?v=GUYRMdcEs00&list=PLllV
waZQkS2omBpLjQm_BAQKsQ7lq86ku
• Bozeman Graphing Excel Spreadsheet 5 min.• http://www.youtube.com/watch?v=yvYvHU83_6Y&list=PLllVw
aZQkS2omBpLjQm_BAQKsQ7lq86ku
Film Clips