A student from Sidney, Australia compares the distance he obtained from the 1-st spark mark to the 20-th spark mark, with the similar result of a student who did the experiment in Gaithersburg, Maryland. Both students operated identical setups powered with 60 Hz AC, reported no missing spark marks, and certified precision of their measurements in four significant figures. What difference in the results was found? Data for the gravity acceleration constant are provided in the text.
A student in Europe performs the same experiment, but the AC frequency there is 50 Hz. How different length of sensitized tape will he need in order to get 20 spark marks, compared to the length of your tape for the same number of marks? Give the result in centimeters.