Home > Subjects > Physics > Level 3 > 3.1 Physics investigation > Key tips

- Subject: Physics
- AS: AS91521
- Level: 3
- Credits: 4
- Internal

## Physics 3.1 Carry out a practical investigation to test a physics theory relating two variables in a non-linear relationship

### Key tips

- Follow the written instructions that will be given to you by your teacher.
- Ask lots of questions before you begin, so you know clearly what is expected of you while carrying out the experiment.
- Keep to the time frame given to you by your teacher.
- Make sure you understand the physics behind the experiment, so you can use this in your discussion.
- Study the generic assessment schedule.
- from
*Te Kete Ipurangi*(TKI) website and structure your write-up to make it easy for your teacher to see the evidence that you have achieved the standard. - You must show how you calculate gradients from your linear (transformed data) graph. Use dotted lines of the graph to show how you calculate rise/run. Do
**not**use your data from your table to calculate the gradient! - Show how you have processed uncertainties from data collection right through data transformation, graphing, gradients, and final calculations. You do not need to show working for each datum you have collected, it is better to show a sample set of uncertainty calculations for one datum, so your teacher can see how you did it.
- Don’t forget to round your uncertainty to one significant figure in your final answer and round the answer to the same decimal place.
- When you transform data, don’t forget to transform the units as well. For example, if you transform time T (in seconds) to time-squared T
^{2}, the units of T^{2}will be s^{2}. - Always give a unit with your gradient. The units of the gradient are the units of the y-variable over the units of the x-variable. For example, a graph of time squared (T
^{2}in s^{2}) against mass (m in kg) will have units s^{2}kg^{-1}. - When you write your discussion, try to show critical thinking in terms of analysing and evaluating your experiment and analysis. There are lots of examples on the generic assessment schedule.