Paper 3 Workout

In this video I have tried to cover the stuff that nearly always comes up. Mostly to do with uncertainty:
How to work out what it is
How to combine uncertainty
How to reduce uncertainty
I hope you find it useful,
Dave

[@tamdf530]

thanks for this got my exam in 2 hours

[@tazzy.x6x]

Same what exam board you doing

[@tamdf530]

@@tazzy.x6x aqa 😁

[@understandingphysicsbydave1349]

GOOD LUCK

[@veelo972]

same

[@liamrennie7982]

Would the uncertainty of the ruler not be equal to the resolution as opposed to half of it because we have a zero error (error when lining an object up at both ends) ?

[@avyx2843]

Hey I just wanted to say thank you for uploading these videos and helping thousands of students across the UK, I found your channel at the time I had my paper 2 and 3 coming and they definitely helped me in the exams!

[@understandingphysicsbydave1349]

many thanks for letting me know

[@ethanmay4385]

Thank you, this has been massively helpful for last minute prep!

[@understandingphysicsbydave1349]

cheers and good luck

[@henrybright7871]

Your videos have helped so much espacially the engineering ones as at my school it is a self studied topic. Thank you so much!

[@understandingphysicsbydave1349]

thanks for the feedback

[@fungamingtv1111]

Thanks so much

[@vqrtex4910]

Thanks

[@milesblack1830]

thanks for your videos

[@understandingphysicsbydave1349]

cheers m8

[@ioannis1097]

Thanks sir you’ve been very helpful🙌

[@understandingphysicsbydave1349]

cheers m8

[@noorshah2038]

Thank you :)

[@understandingphysicsbydave1349]

cheers m8

[@SebastianStone.]

great video Sir!

[@understandingphysicsbydave1349]

cheers m8

[@connorfishr]

cheers dave x

[@understandingphysicsbydave1349]

good luck tomorrow

[@electrotelekino2863]

Hello! i am a bit confused about the meniscus one at 3:05, how is it 6.2?

[@understandingphysicsbydave1349]

its 6.6. my bad

[@user-ku3ob9ov3n]

Isn't it + or - 1 mm for a ruler, as there is uncertainty at both ends of the measurement?

[@understandingphysicsbydave1349]

its the difference between the average and the maximum OR minimum.
Not the difference between the maximum and minimum.
Saying that, if the reading is given as 14mm then you can say that the uncertainty is +/- 1mm as it matches the sig figs.
It's also better to overestimate uncertainty

[@jameskonefal3453]

@@understandingphysicsbydave1349 So would either +- 0.5 mm or +- 1 mm be marked correct in an exam?

[@understandingphysicsbydave1349]

@@jameskonefal3453 +/- 1mm would not be marked wrong

[@JF-qq9od]

@@understandingphysicsbydave1349 Is it not to do with either taking a reading or a measurement. E.g if you're taking a measurement it can be considered taking two readings so the uncertainty is 0.5 + 0.5 is 1mm ? Whereas a simple reading e.g off of a thermometer is +- half the resolution?

[@understandingphysicsbydave1349]

@@JF-qq9od On a recent paper 3 one had to state the absolute uncertainty in a measurement of time from a digital timer.
The time was 15.7s and the answer in the mark scheme was 0.1s (which is clearly equal to the resolution of the instrument).
However, I have seen for a scale (e.g. an analogue meter) it being equal to "half the smallest scale division".
I'm sorry I can't give you a definitive answer, all I can say is that saying that the uncertainty from a ruler with 1mm scale divisions is 1mm will get the mark. (although common sense tells me that it would be half that)

[@MotorwayGaming2018]

Is there one for Edexcel?

[@understandingphysicsbydave1349]

no

[@MotorwayGaming2018]

@@understandingphysicsbydave1349 I see, is there any topics in AQA or OCR A that overlap with Edexcel?