Graph ideas for breaking stress experiment

[acroviak]

Hey.
I have carried out some coursework on breaking stress, and have gathered my results.

I need to do 2 graphs on the experiment, and need some idea's, on what to plot etc.

thanks

[fo3nix]

What is your school year? (i.e., GCSE, pre-GCSE, or A-level?)

[acroviak]

im in A level

[fo3nix]

OK.

What have you measured?

[acroviak]

I measured the diametre of the wire, and the breaking weight. then used these figures to work out the breaking stress. I did the practical 3 times to get an accurate average result.

[factor-fiction]

A starting point would be a graph showing diameter (on x axis) and breaking weight on y axis. Plot your points on here .
Does that give a straight line graph or is it quadratic?
Have you got your readings for that- post them on here and I'll have alook

[acroviak]

the diametres are virtually the same, as the same copper wire is used, throughout. should i have used some different diametres of copper wire? i can always do so.

[factor-fiction]

So the diameter of the wire is the same but you have 3 different readings for weight at which the wire breaks You have then taken an average to get the average result .
I'm assuming the 3 results were pretty similar- if they weren't then this suggests there is another factor at play here. Is teh wire length a factor?
If the diameter is unchanged then I don't think a graph is appropriate. What makes you think you need a graph?
If your project is supposed to have graphs I would have thought that varying the diameter would be a good idea

[New Judge]

I�m rather withfactor30 on this one.

You say you need to do two graphs. Why?

Before preparing a chart of any kind, the first thing you must decide is what you want the chart to demonstrate. This should flow from what your experiment sets out to achieve.

So what is your experiment setting out to demonstrate? Why are you doing it and what are your measurements designed to show? Or is this just an exercise to prove that you can take some measurements and plot a graph or two?

The way you have described what you did, I would not expect to see any significant difference in any of the three measurements (apart from a small difference if, say, the wire was not of perfectly uniform manufacture).

Is this really today�s A-Level material?

[acroviak]

Yes I am in AS Lvl currenty, And I have chosen to do the breaking stress of copper as my coursework.

I ready your comments, and re did the experiment with another thickness of wire, So i have two different diametres, and two different mean values for the breaking stress.

Hopefully having the second variable should make it easier to make a graph.

[Muppit]

You probably ought to plot load vs extension. If I remember correctly, you'll get a fairly uniform linear result until the elastic limit is exceeded at which point you'll get a curve then a PING!

Or something to that effect.