Figure 3 similarly shows the acceleration in the y-direction as a function of time for the device in its case with a mass, m, of 410.69 g and a length, L, of 0.675 m from 30.00 to 35.00 s. As is expected with an unchanging pendulum length, the period is shown to remain constant and was found to be 1.67 ± 0.02 s, not significantly different from the period determined at the previous mass according to a t-test.