One should tie the string to the mass at one end and the stand at the other, and measure the length, L, of the string from the point on the stand to the center of mass of the mass. The uncertainty...One should tie the string to the mass at one end and the stand at the other, and measure the length, L, of the string from the point on the stand to the center of mass of the mass. The uncertainty in the time should be taken as half of the smallest division of the cell-phone timer, and the uncertainty in the length of the pendulum as half the smallest division of the meter stick used to measure the length of the pendulum.
