Compare the methods for calculating g... (1 Viewer)

[Dumsum]

I'm looking at Question 16, part b) from the 2002 HSC exam. The general gist of the question is they've taken measurements from their pendulum and Kim used the results to obtain a mean value for g, while Ali graphed the results and used the line of best fit.

The question reads "Compare Kim's and Ali's methods of calculating g and identify the better approach." It's worth 3 marks.

I'm just unsure of the better approach; because personally I hate doing lines of best fit.

Also for the comparison part, would I just say something like one uses the results themselves and one uses a graph?? I just can't see how this question is worth 3 marks...

 

[thunderdax]

In the comparison, they both use the same data but have different methods of presenting the data and calculating the results.
The better method is the graphing one because it means outliers do not have to be counted. These are points that lie off the general trend of results and therefore aren't included in the line of best fit.

 

[velox]

Yep, by using a line of best fit, the outliers aren't counted and thus the result is more valid. The outliers are generally random errors.

 

[rama_v]

Yep, I did this question a while ago, here was my answer:
"the better method is Ali's method because it takes into account minor fluctuations and averages these out with a line of best fit, adn it also does not take into consideration utliers which distort results. Using the graph, you can determine the value of G by multiplying the length of the string by 4pi squared and dividing it by the value of T^2. This yields a better approximation (9.47) than Kim's method and is thus a better approach to identifying g. "

 

[Dumsum]

Rightio, thanks guys I gave the paper to my Physics teacher to mark today... this was the main question that struck me. I have a habit of freaking out when a question is worth more or less than what I think it should be