# Lab Report How does a good report look like?

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Hi people,

I'm doing Physics SL. and I need some sample lab report to have an idea of how a good one looks like.

My teacher gave very vague instructions how to write a lab report so I seriously need your help.

Many thanks

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There are many sample IA's in the IBSurvival files section, which is available to donators and VIPs.

However if you have any specific questions, I'd be happy to help here

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I don't really know about my specific questions because everything is so vague to me.

My biggest problem I think is about uncertainty. I get it when you add the uncertainty of A and B to get the uncertainty of the product of A and B and things like that. But I don't get the percentage uncertainty. How do you do that?

Another thing, about the graph of the results, so the gradient, in some experiments, is the result that we look for. Like the gradient of the Voltage/current graph. How do you find this gradient though? I plug it in the Ti84 to find the gradient, and i think it works?

About the graph again, how do I present the error bars? My teacher told me that as the results get bigger, the errors get bigger too, so the error bars are not always the same, like constantly 10% or something like that. So we need to find the error bars based on the percentage uncertainty we find. Don't get it here either.

I would really appreciate it if you can help. I know I have tons of questions and it would bother you. I'm sorry.

Thanks so much.

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I don't really know about my specific questions because everything is so vague to me.

My biggest problem I think is about uncertainty. I get it when you add the uncertainty of A and B to get the uncertainty of the product of A and B and things like that. But I don't get the percentage uncertainty. How do you do that?

Another thing, about the graph of the results, so the gradient, in some experiments, is the result that we look for. Like the gradient of the Voltage/current graph. How do you find this gradient though? I plug it in the Ti84 to find the gradient, and i think it works?

About the graph again, how do I present the error bars? My teacher told me that as the results get bigger, the errors get bigger too, so the error bars are not always the same, like constantly 10% or something like that. So we need to find the error bars based on the percentage uncertainty we find. Don't get it here either.

I would really appreciate it if you can help. I know I have tons of questions and it would bother you. I'm sorry.

Thanks so much.

Hey!

The percentage uncertainity is found by dividing the absolute error by the measurement, then multiply it by 100%.

You can find the gradient from the distance of the vertical coordinates divided by the distance of the horizontal coordinates of two points, in other words, Δy/Δx.

The errors usually depend on the measurement and sensibility of instrument. The percentage error increases when the results are smalller, and well, you can probably graph it on Excel.

You can PM me if you need more help.

I got some lab reports i did which were remarked as "very good" by my teacher, too bad they are in Spanish. If you need them, let me now.

Good luck!

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Percentage uncertainty is basically just a way of keep the ratios of uncertainties as you multiply two figures.

For example, if you have a value of 5.63 + 0.05 and another value of 4.5 + 0.5, and you wanted to find the uncertainty of the product of the two:

Find the how much of the number the uncertainty makes up (so to speak):

0.05 is about 0.89% of 5.63

0.5 is about 11.11% of 4.5

So the product is:

5.63 * 4.5 = 25.335 + 12%

And convert back to absolute uncertainty:

12% of 25.34 is about 3.04.

So:

25.335 + 3.04

At least that's how I do it....

Also, about the gradients, to find the uncertainty of a gradient you need to find the minimum gradient and the maximum gradient using the error bars.

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Or you could even use the uncertainty calculator that timtamboy63 wrote.

It makes writing lab reports with uncertainties so much easier and it will calculate percentage uncertainty for you and show you how it did it.

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There are many sample IA's in the IBSurvival files section, which is available to donators and VIPs.

However if you have any specific questions, I'd be happy to help here

Can I take you up on the offer to share "good" or "perfect" lab reports?

I am neither a VIP or a donator; just a simple IB physics teacher struggling to teach labs the IB way to my students

We are not really supposed to share out files that the users donated here. Files are only for people who are VIPs or subscribers. Violating that rule and giving it to someone who has only posted 1 post - which is this one - is probably a bit......... I'm sure you can find TSM (teacher support material) for IB Physics through IBO website. You should also be receiving IB teacher training - your school is meant to provide you that. If you have any other questions, please PM me about it. As far as perfect lab reports are concerned, there are some fabulous posts that tell you what should a good report look like.

Cheers.

Edited by ecieee

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