The value for the acceleration of gravity was measured in this report through the investigation using three different methods, each varying in accuracy, to calculate the period of a pendulum. The period was measured by repeatedly timing the time it took for the pendulum to return to its original position once it was swung from a certain point (for the first method one oscillation was timed, however in the second and third ten oscillations were timed and the overall time was divided by ten; the length of the pendulum rod was altered also for the third experiment to create a varied range of lengths). Using the derived equation for the period of a pendulum the gravity could be calculated. Three different values were achieved by these three different methods, 11.4, 6.7,14.8 and 8.4, compared to the accepted value of 9.8 ms^-2 (Torres, 2378).
Introduction In this experiment I am aiming to investigate the time it takes for a pendulum to complete one cycle of …show more content…
Instead of the substitution of values into equation (1), a graph with the gradient of 1 divided by the square root of the acceleration of gravity is used. The length of the pendulum rod is increased every 2cm from 17cm until it reaches 25cm (i.e. five values). Ten oscillations are measured for each length and divided by ten and this is repeated ten times for each length. An average period is found for each of these lengths along with their uncertainties using the equations (3) and (4). A graph needs to be plotted with the period of the y-axis and 2π√L on the x- axis leading to a gradient of 1/√g. Two lines of best-fit are to be found; one using the standard high/low method and secondly one using the unweighted method of least squares. Gradients are found for each of theses lines (along with its error when using the unweighted method of least squares) and these values rearranged to find the value for gravitational