Skip to content | Accessibility - list of access keys used on this site | Sitemap
Find what you need to know

Home > Subjects > Physics > Level 2 > 2.1 Physics investigation > Key tips

  • Subject: Physics
  • AS: 91168
  • Level: 2
  • Credits: 4
  • Internal

Physics 2.1 Carry out a practical physics investigation that leads to a non-linear mathematical relationship

Key tips

Follow the written instructions that will be given to you by your teacher.

Ask lots of questions.

If you draw a raw-data graph, make sure you can recognise from the shape of the graph the four types of relationships (linear, square, inverse, and inverse square).

You will be provided with a formula for the relationship between the variables.  Use this to help decide the type of relationship and which transformations will give you a straight line graph.  For example if you are investigating the relationship between the distance travelled by an accelerating object, and the time since it was at rest, the relevant formula is d= ½at2 .  So a graph of ‘d’ against ‘t2’ will produce a straight line with a gradient of ½a. 

Make sure you prepare for the assessment by knowing how to transform data from a non-linear relationship to give a straight-line graph.

Draw a careful and accurate straight-line graph with both axes carefully labelled with quantity and unit.  Don’t forget to transform your units.  For example, if one of your graphed variables is time squared (t2) then the units for that axis will seconds squared (s2).  The axis label will look like this: t2(s2). 

Draw a Line of best fit (LOBF) and use it to work out the gradient.  Be careful to use the line, not your data table, to find the gradient.  Show how you worked out the gradient by drawing a triangle on the LOBF.

The units of the gradient are the units of the ‘y’ axis over the units of the ‘x’ axis. For example, a graph of distance against time-squared will have units m/s2 or ms-2.

Give the mathematical relationship in terms of the actual variables, not ‘y’ and ‘x’.  For example a graph of ‘d’ against ‘t2’ with a gradient of 5.1 gives a relationship d=5.1t2

You can use your relationship to work out a value for a physical quantity or constant.  For example a relationship of d=5.1t2 can be equated with the provided formula d= ½at2 to give a=10.2ms-1.

Back to top


People logged in


People surfing this site

Most recent posts

English Level 1
1.6 Speech oral presentation (AS90857)

Posted by: mathsteacher

10:31pm 05.05.2015

English Level 2
English 2.9 Form developed personal responses to independent

Posted by: mathsteacher

11:11pm 18.05.2015

English Level 3 & Scholarship
2014 English- How did it go?

Posted by: cas

4:14pm 24.11.2014

Mathematics Level 1
Statistics (91035, 91036)

Posted by: mathsteacher

10:16pm 05.05.2015

Mathematics Level 2
Algebra (91261, 91269)

Posted by: studybird

6:48pm 10.05.2015

Mathematics Level 3 Calculus & Calculus Scholarship
Using Studyit during the holidays

Posted by: mathsteacher

10:21pm 06.05.2015

Mathematics Level 3 Statistics & Statistics Scholarship
Using Studyit during the holidays

Posted by: mathsteacher

11:15pm 27.11.2014

Sciences Level 1

Posted by: scienceteacher3

6:15pm 23.11.2014

Science Level 2 & 3

Posted by: Doo

9:26pm 17.11.2013

Physics Level 2

Posted by: scienceteacher6

7:43am 18.11.2014

Physics Level 3 & Scholarship

Posted by: DashedDaBomb

5:25pm 26.11.2014

Biology Level 2, 3 & Scholarship
Bio 2.6 Community pattern (New AS 91158) Internal

Posted by: Bionut

11:21am 22.05.2015

Chemistry Level 2, 3 & Scholarship
NCEA for adult leaners - advice needed

Posted by: mathsteacher

10:54pm 22.05.2015

Earth & Space Science
Where to find resources

Posted by: mathsteacher

11:13pm 14.10.2014


Posted by: jun

7:47pm 22.05.2015