UNCERTAINTIES

Question 1

How ti find upabsolute uncertainty of a Custer value using gradient?

Answer 1

Find percentage uncertainty first
- this is done by finding gradient, then line of worse fit
- this is either the STEEPEST IR SHALLOWEST LINE (top of top through bottom of bottom error bar)
- then subract from good gradient / gradient

Okay now multiply this value by the actual value to get the ABSOLUTE UNCERTAINTY

Question 2

How ti draw line of worse fit

Answer 2

Draw steepest or shallowest line with error bars given

• so must pass throihgh top of top error bar and bottom of bottom for steeper, vice Verca for shallowest

Question 3

IMPORTANT
What number of decimal places do you leave uncertainty snd calculated value to

Answer 3

That the uncertainty and the calculated value must be given to same number of DECIMAL PLACES

Question 4

what is reading vs measurement?

Answer 4

Reading is where there is NO ZERO ERROR= the value for zero is perfect

Measurement is when lining up against something twice

Question 5

What is absolute uncertainty in reading vs measuremtn

Answer 5

In reading, it’s just the RESOLUTION/2 (no zero error)

But in a MEASUREMENT it’s absolute uncertainty = resolution (as there is uncertainty in both readings in measurements so they add up)

Question 6

Why in a burette is it then x two?

Answer 6

Because now you’re actually doing a MEASUREMENT so they want you to multiply this by2

Question 7

Examples of measurements vs readings

Answer 7

Measurements = temp, measuring cylinder, digital voltmeter and ammeter (as been calibrated already)

Readings = length, time for stopwatch, vernier calliper micrometer etc

Question 8

So for dingin absolute uncertainty mostly what it’s gonna be for physics

Answer 8

Just the resolution of the thing

Question 9

Okay how ti find UNCERTAINTY IN A A MEAN

Answer 9

find mean

Uncertainty = range of mean /2

Question 10

When adding or subtracting how to find absolute

Answer 10

Absolute = additoj if other absolutes

And then add or subtract original normally

Question 11

Multiplying or dividing how ti find new absolute

Answer 11

First find percentages, add them

Then multiply by the calcuakted vakue

Then leave to SAME DECIMAL PLACE

Question 12

IF THERE IS A NON LINEAR TRANSFORMATION SUCH AS E, LN , LOG , SQAURE SQAURE ROOT ETC

how ti find nee absolute uncertainty based in value and absolute unvertwinties before?

CRAZY IMPORTSNT

Answer 12

FUNCTION (CENTRAL) - FUNCTION (LOWER)

basiclaly ocr do it this way, actual way is function upper - function lower /2

But ocr stupid so USE THIS WAY

Question 13

Uncertainty in gradient

What if one error bar is autistic

Answer 13

Worst fir = highest error bar ti lowest on lowest or just the steepest thst you can draw going through ALL THE ERROR BARS

2) NOW FIND percentage difference between actual gradient
- multiply by calculate value
- leave to same decimal place

If one is autistic can circl and call it an OUTLIER

Question 14

What does it mean if your absolute uncertainty is bigger than normal value

Answer 14

Then redo experiment trash

Otherwise might have ti add constsnt to attempt to find percentage

Question 15

How to deem if experiment succeful

Answer 15

If the actual value falls in your value + the uncertainty range it’s success

If not it’s not success and need to redo

Question 16

And finally what’s the CORREVT way to right absolute uncertainty ti what precision?

Answer 16

1ST SF

But if forget Atleast the same decimal as the cslcuskted value