ph15720 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
PH15720 PowerPoint Presentation
Download Presentation
PH15720

Loading in 2 Seconds...

play fullscreen
1 / 28

PH15720 - PowerPoint PPT Presentation


  • 103 Views
  • Uploaded on

PH15720. Laboratory Techniques - An Introduction to MATHCAD. Introduction. Review of Last Week Arrays, Vectors and Matrices Simple matrix & vector maths Statistics Plotting & analysing data with vectors. Review of Last Week. Entering data with the Input Table

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'PH15720' - azizi


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
ph15720

PH15720

Laboratory Techniques -

An Introduction to MATHCAD

introduction
Introduction
  • Review of Last Week
  • Arrays, Vectors and Matrices
  • Simple matrix & vector maths
  • Statistics
  • Plotting & analysing data with vectors
review of last week
Review of Last Week
  • Entering data with the Input Table
  • Extracting columns from a matrix
  • Creating simple X-Y graphs
  • Formatting graphs
  • Slope & Intercept
resistor example from lecture 4 1
Resistor Example from Lecture 4 #1

Input table as before

Extract Voltage to vector & apply units

Same for current

resistor example from lecture 4 2
Resistor Example from Lecture 4 #2
  • Check on values of vectors
error bars 1
Error Bars #1
  • Add to graph to show uncertainty in y values.
  • Create vector of ‘High’ values
  • Create vector of ‘Low’ values
  • Add as traces to y-axis
  • Add extra x-axis variables
  • Format as error bars
error bars 2
Error Bars #2
  • Use vector maths to get ‘high’ and ‘low’ vectors

Huge error for illustration only

error bars 3
Error Bars #3
  • Add to graph
error bars 4
Error Bars #4
  • Format traces as Error

Error type

Hide Arguments&Show Legend

pre processing data
Pre-Processing Data
  • Use vector maths to pre-process data before graphing
  • Use knowledge of physics to get data into a straight line format
photoelectric effect 1
Photoelectric Effect #1
  • Photoelectrons emitted from metal surface under illumination
  • Illuminate metal with light of different wavelength
  • Measure energy of emitted electrons (Stopping Potential)
  • Keller, Gettys & Skove p976
photoelectric effect 2
Photoelectric Effect #2
  • Equation given in terms of frequency
  • Experimental data given in wavelength  convert

Planck’s constant

StoppingPotential

Electronic

Charge e

Threshold Frequency

Applied Frequency

converting wavelength to frequency
Converting Wavelength to Frequency

- n=frequency (Hz)

- c= velocity of light (3x108m/s)

- l= wavelength (m)

- Valid for all electromagnetic radiation

photoelectric effect 21
Photoelectric effect #2
  • Use resource centre for physical constants
  • Watch for confusion of e & q
  • Useful functions (look-up in help system)
    • slope(vx,vy)  slope of line
    • intercept(vx,vy)  intercept with axis
stopping potential equation
Stopping Potential Equation
  • Vs  Stopping Potential
  • n  Frequency of radiation
  • n0 Threshold frequency
  • h  Planck’s constant
  • q  Electron Charge
photoelectric effect 3
Photoelectric Effect #3

Curves for two different metals shown

Slope of lines = h/q

Intercept with x-axis (Vs=0) at Threshold Frequency (Different for each metal)

power law
Power Law
  • Systems in the form:Y=AeBx
  • Examples:
    • Cooling
    • Radioactive Decay
    • Compound Interest
  • B is time constant or rate constant
power law1
Power Law
  • Take logs of Y values straight line
  • intercept gives ln(A)
  • slope gives B
power law example 1
Power Law Example #1
  • Data in input table as before
  • Extract Columns
power law example 2 normal plot
Power Law Example #2- Normal Plot

Useless – No Information

power law example 3 format y scale log
Power Law Example #3- Format y scale log
  • Straight line => power law
  • Need to get slope & intercept
power law example 4
Power Law Example #4
  • Take log of y data
  • Calculate slope & intercept
  • Display A&B
  • Create model
review of data handling 1
Review of Data Handling#1
  • Use of Input Table
  • Column Extract Operator M<>
  • Add units if needed
  • Plot vector vs vector
  • Add Error bars
review of data handling 2
Review of Data Handling#2
  • Extract Information from data
    • slope()
    • intercept()
  • Pre-processing
  • Handling power law data
  • Create model & compare with data