Equipment used:
Thread, dense spherical mass like a marble or a bearing, perhapsabout 0.5 – 1.0 cm in diameter. Otherwise, use a
mass that is approximately spherical, e.g., a tangerine orapple.
Method of obtaining g:
Measure the period of 4 lengths of thread from 75 cm to 1.50 cm.Be sure to measure the length from the support
point to the center of mass of the spherical mass at the bottom endof the thread. For each length of thread, pull
the string from the bottom mass out to about 10 degrees from thevertical, then let the pendulum oscillate back
and forth 20 times while measuring the time with a stopwatch.Determine the period, T, by dividing the elapsed
time by 20.
Plot the period squared versus the length of the pendulum. Theresulting curve should be a straight line with a
period involving the acceleration of gravity. Put your data for thelength of the pendulum and the period squared
into Excel. Use LINEST to find the best fit slope for the data andthe error in the slope. Calculate the acceleration of
gravity and the estimated error of the measurement for g.
Please give an excel file here.
