There are a few different graphing software packages that can make P2.1 graphing quick and "easy"... if you know how to drive the software...
Excel
NZ Grapher
LoggerPro
NZGrapher is advised for any student with a chrome-book or who does not have excel or LoggerPro.
LoggerPro no longer costs anything. It can be downloaded for Mac or PC from this site: https://www.vernier.com/downloads/logger-pro-updates/
And just in case that site stops working: here's a direct link from a google drive: save and install:
It is not recommended you even try to use google-sheets to do P2.1 graphs. In short, google-sheets is not good enough and not as good as NZgrapher or excel or logger-pro. While google-sheets can be used in Level 2 physics, it cannot be used in Level 3 physics - so best to learn a method that you can use for 2 years.
Below are a few youtubes for each workable graphing software above.
You should check with your teacher and follow the processes they want you to follow.
Many other videos exist. Check with your teacher before following any video you find.
FYI: below is a breakdown of what is required to Achieve, get Merit or get Excellence: from the NCEA standard (version 2):
To get Achieved: you need all 3 bullet points below:
collecting data relevant to the aim based on the manipulation of the independent variable over a reasonable range and number of values
drawing a graph that shows the relationship between the independent and dependent variables
writing a conclusion which describes the type of mathematical relationship that exists between the variables.
Notes:
Remember the requirement for "reasonable range": For a good range your largest IV divided by your smallest IV should be at least 3, if not 4 or more.
For describing the "type of mathematical relationship" remember almost every L2 experiment starts out as 1 of the following: square, square-root, inverse or inverse-square.
Your graph of DV vs IV will be a curve.
To get Merit: you need the Achieved package above AND all 3 bullet points below:
controlling the variable(s) that could have a significant effect on the results
using technique(s) that increase the accuracy of the measured values of the dependent (and independent, if appropriate) variable
writing a conclusion that describes the mathematical relationship obtained from the experimental data.
Notes:
You need the essential control (or controls) that would have changed your DV measurements. Don't include silly things or things that would not have substantively changed your measured DV values in your experiment. Controls are almost always things you chose to keep constant during your entire experiment - that could have changed all of your DV measurements.
Many confuse controls for accuracy improvement techniques - so be careful.
You need to get the equation of your 2nd graph (or linear graph). This is the graph you make with a transformed IV or DV. You will almost always either square, square-root, inverse or inverse-square either your DV or IV depending on your 1st graph or the theoretical equation in your instructions.
When writing your equation of your straight line transformed graph: remember, we NEVER include units in equations. The pattern will be: (whatever you have on the vertical axis) = (your gradient) x (whatever you have on the horizontal axis) + (your vertical intercept). Use symbols for each graph axis concept. Round off values a bit from the numbers in excel, logger-pro or NZgrapher.
You need to describe the equation you got from your linear graph. Remember that no equation in physics includes units.
For Excellence: usually only from your discussion and only if you have Achieved & Merit parts above:
You need at least 2 parts done well, or 3 parts done "almost well".
the relationship between the findings and physics ideas
a justification for why a variable needs to be controlled
a reason why there is a limit to either end of the value chosen for the independent variable
a description of any unexpected results and a suggestion of how they could have been caused and/or the effect they had on the validity of the conclusion.
a description of any difficulties encountered when making measurements and how these difficulties were overcome
Notes:
To fully explain how your results pair up with physics ideas include diagrams and explained equations whenever possible.
To justify your controls, focus on controls that could have significantly changed your results. Explain how your DV measurements would have changed, how your graph points would have changed, and how your gradient or intercept of LOBF would have changed. Use sketches of graphs whenever possible to help make your point clear.
For reasons why you chose the smallest or largest IV value: focus on the trustworthiness of your measured DV at those extreme IVs. If the human reaction time was too large of a proportion of the DV measurement, the measurement and that IV is not worthy of including. If there are physics reasons why an extreme IV could not work or the relationship would change, then explain that in detail (using diagrams and equations whenever possible).
For "unexpected outcomes" that usually is about explaining in detail why you got a gradient that is not what you expected. An intercept close to zero is not worthy of an excellence-explanation if you expected a zero intercept.
Do not expect to get an excellence-point on describing difficulties. This is rarely deep enough to get excellence.
Finally: below are 2 summaries explaining how L2 students make errors or leave things out and either fail, miss out on Merit or fall short of gaining Excellence. Check with your teacher too!