Hey guys if you found this useful, you will probably find my Physics Workbook very useful for practice: zphysicslessons.net/ultimate-uncertainties-physics-workbook-
sure! It's 50 multiple choice questions organized by difficulty to give you a good work out. In a previous comment though you mentioned you struggle more with written questions, so if you find calculating uncertainties easy, this is probably not the workbook for you. This video covers similar questions: ruclips.net/video/LQVB2G7aabY/видео.htmlsi=95LhXKYmo9SndDE0
For multiplying/dividing part of combining uncertainties, I understand why we use the percent uncertainties (different units), but why do we add them? I understand when we add or subtract values, but not for multiplying and dividing.
Thank you so much for the comment! Great to hear! Sadly only the videos are available, I would generally recommend doing your own notes from videos/textbooks as it can point your direction to what's important, note it and annotate etc. Good luck revising!
No yet, but thanks for the idea. For a standard micrometre the standard can be summarized in: twist the micrometer gauge until what your measuring (say a wire) is feeling a little bit of pressure from the micrometer (not too much as it will damage it). Then each turns of the wheel (line on the gauge) represents 0.5 mm. For exam questions remember to say measure the diameter on mutliple parts along the wire, then average. Hope this helps!
Hi, I may have misunderstood something here, but at 26:50, you measured the length as 0.15m, with the smallest reading on the ruler as 0.001m. Wouldn’t the uncertainty here be +/- half of that value? I’ll give an example to explain my thoughts process. If you had a meter ruler and measured something to be 0.54m, and the smallest possible reading of the ruler is 0.01m, then wouldn’t the only possible deviation of the measurement from the true value be from 0.535 and 0.545, as anything lower or higher respectively would give you a different initial reading like 0.53m or 0.55m, meaning the deviation either way of what you measured is really only 0.005m making the uncertainty 0.54 +/- 0.005m? Please correct me if I have misunderstood what you were saying. Thankyou
Interesting question, there are two ways to think about it, one that you are actually taking two separate measurements of two separate coordinates, each of absolute uncertainty of half a mm. Combining them to get a total uncertainty of 1 mm (this appears a lot in aqa and edexcel), OCR generally assumes absolute uncertainty to be the smallest measurable value. Hope this helps!
not necessary however for further calculations the units need to be the same on the left and right. I do this a couple of minutes later in the video in terms of meters. Could also be done in cm. Hope it helps!
I originally made these videos for OCR A, however all syllabuses are extremely similar, at around 90%. The best way to use them is use your syllabus as a check list. Hope this helps!
at 25:23, why is the absolute uncertainty 0.125 instead of 0.13? i thought that the absolute and percentage uncertainty needs to be the same significant figures as the number
Sir at 16:18 you were putting p=f/a, which is mg/a then why you put 1/2mg÷a (you told half hecause of ' foot ' , sir i didnt get the logic??). Can you explain why foot means 1/2?
It depends on the amount of significant figures given for the uncertainty in the question. If it is 1 then, yes. If it is more, then that number. Hope this helps!
Mostly due to historical reasons. Current is just very easy to measure with an ammeter. Theoretically you can choose any other to be a base unit and redefine all the other units in terms of that.
Thank you so much for your efforts sir! By any chance can i have access to this mind map/the doc you are writing these notes in? Would really help for my revsion later on...
would it still be systematic error if the values slowly only increase\decrease at higher and higher values/ the values only increase\decrease at higher and higher values? or lower?
@@zhelyo_physics at high values the readings increase by larger and larger amounts, ( on a mass balance for eg: after 150 kg it increases more and more, and under 20 kgs it decreases by a larger amount)
Sir, I want to use your playlist to only study for AS-level stuff. Can you please tell me what videos come under units one and two? Also, can these videos be used to study for January 2025 exams edexcel?
Hi, I used Microsoft Whiteboard. The new version of this though runs very slowly and I might look at alternatives. Still worth it for notes though, it's also free.
Hi, this + my all of vectors video covers all of Module 2 OCR Physics A. If you are doing a different exam board you can google the syllabus and use the time stamps to see if there is anything different.
most of my videos are applicable to all exam boards and if not I tend to leave a note in the title. I don't have specific Edexcel past paper walkthroughs though if this is specifically what you are looking for. Hope this helps!
some exam boards take that to be the case (annoying as it should be standardised), if you are doing aqa they typically take it as resolution/2. Hope this helps!
@@zhelyo_physics i dont think so. 100% is 1. If you write down 5÷20×100 without any explanation, the result can only be 25 but never 25%. You can say it is a habit or a trick to make calculation easier, but it is mathmatically wrong. thanks for your reply anyway.
There might be some minor differences but the physics across all exam boards is over 90% similar. So check with your syllabus which you should be easily be able to google. Good luck and drop a comment if something doesn't make sense! : )
yep! Physics is physics and the syllabuses are incredibly similar, always have a check with the spec before any resource/test though for any minor differences.
@@zhelyo_physics Sir ,in that estimation question ... If the pressure is exerted by only one foot won't that foot exert more force than that of standing on two feet?
the question assumes that a person is standing on two feet and asking for the pressure on one of them. The estimated area is already for 1 foot with those dimensions. Hope this helps!
@@zhelyo_physics I believe that the person was talking about the Force on the numerator itself not needing to be halved. If a person steps on a scale with both feet and weighs 70kg, their mass is still read as 70kg on the scale even if one foot is planted on the scale. So the force is not halved. You stated I think that the area of *one* “shoe”/ foot is 0.03m^2, so there does not need to be any halving for one foot. The equation can remain as mg/A which is (70x9.81)/0.03=22890 Pa
@@Miftahul_786 that would be correct if the person was standing on one foot. My question assumed the force to be equally shared between two feet, i.e. what is the pressure from a single foot when a person is standing on two feet. I can see the ambiguity, though! : )
what does that mean if the mass is the same no matter how many feet are on the scale. surely you just work out the weight of the person by doing 70*9.81 then dividing that by the area of one foot since the weight doesnt half with one foot. im so confused @@zhelyo_physics
ok is the person standing on the scale with one foot and the other foot raised or is the person standing on the scale with one foot and standing on the floor with the other one @@zhelyo_physics
Hey guys if you found this useful, you will probably find my Physics Workbook very useful for practice: zphysicslessons.net/ultimate-uncertainties-physics-workbook-
May I ask you what do I get in this workbook. Thanks
sure! It's 50 multiple choice questions organized by difficulty to give you a good work out. In a previous comment though you mentioned you struggle more with written questions, so if you find calculating uncertainties easy, this is probably not the workbook for you. This video covers similar questions: ruclips.net/video/LQVB2G7aabY/видео.htmlsi=95LhXKYmo9SndDE0
Sir can I use this workbook for AQA exam board ?
@@ES-rv5ik absolutely, hope it's useful
@@zhelyo_physics
Thank you for you reply sir
how about the other workbooks ?
Are they valid for AQA exam board as well?
Hi from Zimbabwe 🇿🇼 my brother I really appreciate your content. Keep on Making physics a fun subject to learn
zim gang
i'm not doing physics a-levels but i love these videos! i'm in year 11 rn. THANK YOU for making this so fun
thanks for the comment! I actually have a GCSE channel too if it helps: www.youtube.com/@ZGCSE Good luck with your GCSEs!
Same, preparing to do physics a level of my GCSEs go well
Just finished yr11
i am lowkey in love with your videos at this point
Thank you!! Your videos are a life saver for exams🙏
Anytime! Glad to hear!
I just started your 48 video playlist, you are saving my april mock
best of luck going through the content. Let me know if something doesn't make sense!
great lecture man, may god bless you
thank you very much for the comment!
SOOO HELPFULL OMGGG I LOVE YOU
Glad this is helpful!
For multiplying/dividing part of combining uncertainties, I understand why we use the percent uncertainties (different units), but why do we add them? I understand when we add or subtract values, but not for multiplying and dividing.
This is super useful thank you!! are you going to release the notes too, that would help so much😁
Thank you so much for the comment! Great to hear! Sadly only the videos are available, I would generally recommend doing your own notes from videos/textbooks as it can point your direction to what's important, note it and annotate etc. Good luck revising!
These videos are so good thanks
Thank you so much for the comment!
Do you have a video on how to read/use a micrometre and Vernier Scale?
Thanks
No yet, but thanks for the idea. For a standard micrometre the standard can be summarized in: twist the micrometer gauge until what your measuring (say a wire) is feeling a little bit of pressure from the micrometer (not too much as it will damage it). Then each turns of the wheel (line on the gauge) represents 0.5 mm.
For exam questions remember to say measure the diameter on mutliple parts along the wire, then average. Hope this helps!
@@zhelyo_physics thank you!
best physics teacher on the planet
Thank you so much for the kind comment!
what software is this? and can we download these notes?
It's microsoft whiteboard and just the videos for now but they cover most of the spec.
thanks alot!!! really helpful
Can Someone please suggest a similar kind of channel for A level Biology...
I really need it.
btw, great conceptual videos. Really helpful for exams
thanks a lot for the comments! I am no expert in Biology but I think Miss Estruch Biology is a very good channel for A level Bio. Good luck!
Thank you@@zhelyo_physics your recommendation is really helpful. I checked that channel out and it turned out to be a real help.
@@hardik05jain try behology
Hi, I may have misunderstood something here, but at 26:50, you measured the length as 0.15m, with the smallest reading on the ruler as 0.001m. Wouldn’t the uncertainty here be +/- half of that value? I’ll give an example to explain my thoughts process. If you had a meter ruler and measured something to be 0.54m, and the smallest possible reading of the ruler is 0.01m, then wouldn’t the only possible deviation of the measurement from the true value be from 0.535 and 0.545, as anything lower or higher respectively would give you a different initial reading like 0.53m or 0.55m, meaning the deviation either way of what you measured is really only 0.005m making the uncertainty 0.54 +/- 0.005m? Please correct me if I have misunderstood what you were saying. Thankyou
Interesting question, there are two ways to think about it, one that you are actually taking two separate measurements of two separate coordinates, each of absolute uncertainty of half a mm. Combining them to get a total uncertainty of 1 mm (this appears a lot in aqa and edexcel), OCR generally assumes absolute uncertainty to be the smallest measurable value. Hope this helps!
@@zhelyo_physics yes that clears things up. Thankyou so much
hey i have my first AQA A Level Physics lesson tommorow hopefully this is valid for AQA :)
it definitely will! Good luck on your first lesson!
thank you man you helped me a lot keep it up
anytime, thanks for the comment!
Your videos are amazing! You should also do one on alternating current, rectification, rms, etc.
26:29
Don't we have to give the absolute uncertainty in terms of the measurement of the value?
e.g 15cm±0.001cm
not necessary however for further calculations the units need to be the same on the left and right. I do this a couple of minutes later in the video in terms of meters. Could also be done in cm. Hope it helps!
@@zhelyo_physics Thanks! Your videos are helping me a lot
Hello Sir , Thank you so much for your wonderful well taught videos , I just wanted to ask wich syllabus are you specifically going by?
I originally made these videos for OCR A, however all syllabuses are extremely similar, at around 90%. The best way to use them is use your syllabus as a check list. Hope this helps!
at 25:23, why is the absolute uncertainty 0.125 instead of 0.13? i thought that the absolute and percentage uncertainty needs to be the same significant figures as the number
correct! Of course, just testing if anyone would notice of course.
@@zhelyo_physics 😂😂😂
does this playlist allow OCR A A-Level physics too
absolutely, it covers 100% of the OCR spec
Sir at 16:18 you were putting p=f/a, which is mg/a then why you put 1/2mg÷a (you told half hecause of ' foot ' , sir i didnt get the logic??). Can you explain why foot means 1/2?
So half of the force is distributed on each foot : ) hope this helps!
Hello, shouldn't the aboslute uncertainty be writting in 1 significant figure? like instead of 0.125 it should be 0.1??
It depends on the amount of significant figures given for the uncertainty in the question. If it is 1 then, yes. If it is more, then that number. Hope this helps!
Wonderful!!!
Thank you for the comment!
Hi
I dont quite understand why current is a base unit. Its charge per second, but a second *is* a base unit by itself??
Mostly due to historical reasons. Current is just very easy to measure with an ammeter. Theoretically you can choose any other to be a base unit and redefine all the other units in terms of that.
Thank you so much for your efforts sir! By any chance can i have access to this mind map/the doc you are writing these notes in? Would really help for my revsion later on...
anytime! Sorry only the videos are accessible. Good luck revising.
would it still be systematic error if the values slowly only increase\decrease at higher and higher values/ the values only increase\decrease at higher and higher values? or lower?
Hm, I would need to look at the exact situation. If they don't increase by the same amount across all readings it can't be a systematic error.
@@zhelyo_physics at high values the readings increase by larger and larger amounts, ( on a mass balance for eg: after 150 kg it increases more and more, and under 20 kgs it decreases by a larger amount)
@@zhelyo_physics if it increases with a constant factor like 1.1 or any constant number than yes
At 28:09 isnt the absolute uncertainty for 0.15 m should be 0.01 , instead of 0.001?
mmm 1mm in metres is 1x10^(-3)m hope this helps!
Hi, have you done any exam questions on this topics. Thanks for you videos.
anytime! Yes, lots of them. Check this video out for starters: ruclips.net/video/LQVB2G7aabY/видео.htmlsi=ZNdGKYzZRU_IDPRq
Sir, I want to use your playlist to only study for AS-level stuff. Can you please tell me what videos come under units one and two? Also, can these videos be used to study for January 2025 exams edexcel?
The best thing to do is to get a print out of your specification and use it as a checklist. Best of luck preparing, you got this!
Which software did you use for the notes in the video?
Hi, I used Microsoft Whiteboard. The new version of this though runs very slowly and I might look at alternatives. Still worth it for notes though, it's also free.
thanks
anytime
TIME TO BINGE THISS WHOLEE PLAYLIST
Good luck! Drop a comment if something doesn't make sense.
Does this syllabus cover all of the syllabus, if no, which ones are missing?
Hi, this + my all of vectors video covers all of Module 2 OCR Physics A. If you are doing a different exam board you can google the syllabus and use the time stamps to see if there is anything different.
Sir, do you do edexcel physics past paper questions?
most of my videos are applicable to all exam boards and if not I tend to leave a note in the title. I don't have specific Edexcel past paper walkthroughs though if this is specifically what you are looking for. Hope this helps!
why did u use uncertainty = resolution, not resolution/2?
some exam boards take that to be the case (annoying as it should be standardised), if you are doing aqa they typically take it as resolution/2. Hope this helps!
when you calculate the percentage uncertainty, you should multiply 100% instead of 100.
Hi it's essentially the same way of writing it out. Both would be accepted.
@@zhelyo_physics i dont think so. 100% is 1. If you write down 5÷20×100 without any explanation, the result can only be 25 but never 25%. You can say it is a habit or a trick to make calculation easier, but it is mathmatically wrong. thanks for your reply anyway.
Think of the percentage as a unit at the end, at an A-Level exam you would not be marked down for it : )
does your playlist for AS Level physics covers all the topics as per the requirements for cambridge Alevels...
There might be some minor differences but the physics across all exam boards is over 90% similar. So check with your syllabus which you should be easily be able to google. Good luck and drop a comment if something doesn't make sense! : )
Are these videos valid for edexcel international a levels board
yep! Physics is physics and the syllabuses are incredibly similar, always have a check with the spec before any resource/test though for any minor differences.
Sir, thanks for the video! Can you share the notes?
My pleasure! Sorry pal, only the videos are available
@@zhelyo_physics Sir ,in that estimation question ...
If the pressure is exerted by only one foot won't that foot exert more force than that of standing on two feet?
standing on two feet yes, but the question was asking about to pressure from just 1 foot. Hope this helps!
at 38:08 are we able to rewrite the final answer as 25.0 +- 4% ??
yep!
At 5:36 why is 10/10^-3 equal to 10^4, how did you get that?
10/10^(-3)=10/(1/10^3)=10*10^3=10^4 Hope this helps!
your videos are amazing!!! but i would really appreciate if i can have a free revision worksheet to work on :)
Would it be correct to say that the absolute uncertainty from a graph is: line of worst fit gradient - line of best fit gradient?
Absolutely yes! : )
For 16:32
doesnt the mass weight remain the same even standing on one foot?🤔
I think you have to divide the area by two
the question assumes that a person is standing on two feet and asking for the pressure on one of them. The estimated area is already for 1 foot with those dimensions. Hope this helps!
@@zhelyo_physics I believe that the person was talking about the Force on the numerator itself not needing to be halved. If a person steps on a scale with both feet and weighs 70kg, their mass is still read as 70kg on the scale even if one foot is planted on the scale. So the force is not halved. You stated I think that the area of *one* “shoe”/ foot is 0.03m^2, so there does not need to be any halving for one foot. The equation can remain as mg/A which is (70x9.81)/0.03=22890 Pa
@@Miftahul_786 that would be correct if the person was standing on one foot. My question assumed the force to be equally shared between two feet, i.e. what is the pressure from a single foot when a person is standing on two feet. I can see the ambiguity, though! : )
what does that mean if the mass is the same no matter how many feet are on the scale. surely you just work out the weight of the person by doing 70*9.81 then dividing that by the area of one foot since the weight doesnt half with one foot. im so confused
@@zhelyo_physics
ok is the person standing on the scale with one foot and the other foot raised or is the person standing on the scale with one foot and standing on the floor with the other one
@@zhelyo_physics
is the percentage uncertainty in the last question -40%?
Hi, it's 4%, the denominator in the fraction is 4.0 not 40.
can you please explain how you got 1/2mg in the estimates section??
Sure, just assuming that each foot is carrying half the weight. Hope this helps!
@@zhelyo_physics yep, got it. Thank you.
@@zhelyo_physics But is that the case sir it wont it be Same amount of mass the foot is caarying the whole mass
this can help in physics a2 p5 right?
Yep, check with your syllabus though.
so will all these videos with lots of practice on past papers will guarantee me an A or B
Nothing can guarantee a grade, but this will help a lot.
is this for aqa?
Hi, it's applicable to all exam board but best to check with the aqa spec for differences. I teach OCR and the content is very similar.
Bruh Can U provide the pdf note of the whole AS Topics
Sorry only the videos are available, you can use them to create your own notes though.
W
Hi from Zimbabwe 🇿🇼 my brother I really appreciate your content. Keep on Making physics a fun subject to learn