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Looking for Guide for Paper 3 Answering Techniques (Bio/Chem/Physics)

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Hello there I'm a private candidate in Malaysia doing CIE A Levels,
do you guys can recommend some links/documents on answering Paper 3 Answering Techniques.

Because I have no clue on answering the paper 3 and the appropriate to learn to do so.
Everything is based on my own :(
 
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These questions :(
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The percentage uncertainty can be found by dividing the least count of the measuring instrument, with the measured value and then multiplying it with 100. Like this:
%age uncertainty = least count/measured value * 100

But here i think the the variable 't' refers to time. The measurement of time is an exception to this. Measurement of time involves human reaction error, so it's not possible for the uncertainty of time measurement to be the least count of stopwatch. The human reaction error causes this uncertainty to be larger than the least count of stopwatch. It's often 0.2s in most cases. So here you may find the %age uncertainty in time as:

0.2/measured value * 100

Your second question involves the calculation of the constant 'k' from the two values of 'v' and 'd' you might have calculated before. This calculation is pretty simple as all you need to do is to substitute the values in to the given equation and equate for the values for 'k'.
The next part asks you to prove whether the given equation v = kd^2 is valid or not. Here you need to find the percentage difference between the two values of 'k' calculated. Let your first value of k you calculated in the previous part to be k1 and the second to be k2. Then the percentage difference will be calculated as:

(k2-k1)/k2 * 100.

Here if the percentage difference you calculated comes up to be less than or equal to 15% then the given relation is valid otherwise it's not. After showing the calculation for %age difference, you may write the answer as:

"As the percentage difference between the values of k is <=15%, therefore the the given relation is valid". Or if the %age difference is beyond 15% then it may go like this:
"As the percentage difference between the values of k is >15%, therefore the given relation is invalid."

Hope you understood. :)
 
Messages
123
Reaction score
22
Points
38
The percentage uncertainty can be found by dividing the least count of the measuring instrument, with the measured value and then multiplying it with 100. Like this:
%age uncertainty = least count/measured value * 100

But here i think the the variable 't' refers to time. The measurement of time is an exception to this. Measurement of time involves human reaction error, so it's not possible for the uncertainty of time measurement to be the least count of stopwatch. The human reaction error causes this uncertainty to be larger than the least count of stopwatch. It's often 0.2s in most cases. So here you may find the %age uncertainty in time as:

0.2/measured value * 100

Your second question involves the calculation of the constant 'k' from the two values of 'v' and 'd' you might have calculated before. This calculation is pretty simple as all you need to do is to substitute the values in to the given equation and equate for the values for 'k'.
The next part asks you to prove whether the given equation v = kd^2 is valid or not. Here you need to find the percentage difference between the two values of 'k' calculated. Let your first value of k you calculated in the previous part to be k1 and the second to be k2. Then the percentage difference will be calculated as:

(k2-k1)/k2 * 100.

Here if the percentage difference you calculated comes up to be less than or equal to 15% then the given relation is valid otherwise it's not. After showing the calculation for %age difference, you may write the answer as:

"As the percentage difference between the values of k is <=15%, therefore the the given relation is valid". Or if the %age difference is beyond 15% then it may go like this:
"As the percentage difference between the values of k is >15%, therefore the given relation is invalid."

Hope you understood. :)
About the percentage difference between the values of k to be valid to support the relation, what is the theory behind 15%?
 
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About the percentage difference between the values of k to be valid to support the relation, what is the theory behind 15%?
Actually, there's no theory behind it. It's up to you. If you consider that you made very little errors while performing, the percentage difference could also be less than or equal to 10% for the relation to be valid. But it should be reasonable. Like if you take that that percentage difference is less than 5% for the relation to be valid; it's totally illogical as no-one is such a superman to perform the practical with so little numbers errors!
 
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