IB Physics-Topic#1 Uncertainty -Qc#9-A rod is suspended horizontally by two vertical strings

In an investigation to measure the acceleration of free fall a rod is suspended horizontally by two vertical strings of equal length. The strings are a distance d apart. When the rod is displaced by a small angle and then released, simple harmonic oscillations take place in a horizontal plane.
The theoretical prediction for the period of oscillation T is given by the following equation
where c is a known numerical constant. State the unit of c.
T = c/d√g
In one experiment d was varied. The graph shows the plotted values of T against. Error bars are negligibly small. Draw the line of best fit for these data.
Suggest whether the data are consistent with the theoretical prediction.
e. The numerical value of the constant c in SI units is 1.67. Determine g,
using the graph. [2 marks].
Topic1 Measurements and uncertainty -Playlist: