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 Laboratory Techniques 
 An Introduction to MATHCAD

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 Review of Last Week
 Dealing with experimental Data

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 IF YOU DON’T UNDERSTAND – ASK!!!
 Explain your work
 Read the question
 Don’t use single character names
 Don’t redefine dimensions (m,s)

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 Equations in physics given in general form
 Need to translate for specific problem

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 5 stage process
 Get data into MathCAD
 Process data (scale, units etc)
 Plot Data
 Fit curve (line) to data
 Compare theory with experiment

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 Way of storing related data
 Experimental Results
 Coefficients
 Solutions to DEs
 3D position/velocity/force
 Single Name – Many values

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 Vector – 1dimensional
 Matrix – 2dimensional
 Array – general term, covers both

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 Put data in matrix
 1 column per measurement
 1 row per data point
 Use Input Table
 Table resizes & scrolls as needed

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 Resistor Experiment
 Apply voltage, measure Current

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 Extract columns with column operator M^{<>}
 Insert into worksheet from
 Fill in column number to extract
 Numbering starts at 0

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 Single column
 Converted to base units
 Scroll bars if needed

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 XY Plot can plot 1 vector against another, if both vectors have same
number of elements
 Use plot formatting to change to single points

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 Only simple straight line fits for now
 slope(Vx,Vy)
 intercept(Vx,Vy)
 Details in help system
 Units carry through calculation
 Sometimes need 1/slope

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 Create function
 Plot on same graph as experimental data
 Use multiple variables on x and y axes
 Separate items on axes with commas

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 Function gives theoretical current
 Test function at a couple of points

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