Physics/Maths question
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My physics teacher told us to find out, over the chinese new year period, why 4 is not equal to 4.0 and why 1 1/3 ( one and one third) is not equal to 1.34 . Please explain to me.
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isn't 1 1/3 = 1.333333333333333333333 which is definitely not 1.34
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go tell yr teacher at once this:
pls go home n revise yr maths again.
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Let me guess... You are in sec 3 this year?
Anyway, this has got to do with significant numbers, under chapter Physical Quantities and Units.
4 means the value can be between 3.5 to 4.499999
4.0 means the value can be between 3.95 to 4.0499999 -
Hey eagle do you want to share something about complex numbers?
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Your maths teacher will tell you 4 is always equal to 4.0. As for physics, I still do not have a clue.
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Originally posted by Garrick_3658:
Hey eagle do you want to share something about complex numbers?
It's out of O level syllabus. Anyway I have stated the reason why it is different...
A level physics also do not deal with complex numbers. Complex numbers in physics is dealt with at much more advanced levels.... for e.g. simple harmonic motion, where it is used to solve their second order differential equation (along with trigo inside) easier... Then the complex value is ignored.
Also, in electrical engineering, complex numbers are used in circuits, where there are capacitors and inductors, in something called impedance of the circuit. The real value of the impedance is what we will learn as resistance.
All these are already out of A level syllabus, where you only learn complex numbers and argand diagram in H2 Maths... Not much... mildly interesting only...
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Originally posted by StealthLeo:
Your maths teacher will tell you 4 is always equal to 4.0. As for physics, I still do not have a clue.
Physics place a lot of emphasis on accuracy and significant figures. In A level physics, you will also learn to state in terms of uncertainties, i.e. 4 ± 0.1, 4.0 ± 0.02 etc etc
The main difference is that 4 means a larger range of values as compared to 4.0;
or... 4.0 is more accurate than 4. -
Originally posted by eagle:
Physics place a lot of emphasis on accuracy and significant figures. In A level physics, you will also learn to state in terms of uncertainties, i.e. 4 ± 0.1, 4.0 ± 0.02 etc etc
The main difference is that 4 means a larger range of values as compared to 4.0;
or... 4.0 is more accurate than 4.Understood. My physics has not always been good. Uncertainties and precision have not occured in my mind for this qn.
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Hi,
In Physics, 4 and 4.0 are not the same. In Maths, an exact value is written as it is, i.e. 4 and not 4.0.
4.0 conveys the idea of an uncertainty of plus or minus 0.1, so the actual value may be between 3.9 and 4.1.
Thanks!
Cheers,
Wen Shih -
ah shm, finally i know what this is.
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A lvl pple start coming in
Good question by TS!
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4.0 more accurate than 4? i thought shld be, 4.0 more precise than 4
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Originally posted by eagle:
A lvl pple start coming in
Good question by TS!
Thank you. I understand now. Thank you wee_ws. -
Originally posted by SBS261P:
4.0 more accurate than 4?
i thought shld be, 4.0 more precise than 4
yup.... that's a better term... my bad