In the case that your ICA file doesn't open, it is highly likely that you do not have the correct software application installed on your PC to view or edit ICA file extensions. If your PC opens the ICA file, but it's the wrong application, you'll need to change your Windows registry file association settings.
He found the period of the planet's revolution around the Sun in years would be equal to the cube of its average distance from the Sun in astronomical units. Let us suppose we find an asteroid with a perihelion distance of 3 AU, and aphelion distance of 5 AU. Calculate its semimajor axis (average distance from the Sun) and use Kepler's Third Law to find its orbital period in years.
Calculate the time of one oscillation or the period (T) by dividing the total time by the number of oscillations you counted. Use your calculated (T) along with the exact length of the pendulum (L) in the above formula to find g.. This is your measured value for  g. . Repeat the above procedure for 3 more cases. Choose 3 other values for L between 125cm and 158cm and record them in the Table in rows 2, 3, and 4.