In a school laboratory, a student determines the acceleration due to gravity with a simple pendulum.
(i) Explain briefly how the student should determine the time period from observations of 20 complete oscillations.
(ii) The length of the pendulum is measured as 0.94 m. The time taken for 20 oscillations is 38.6 s. Calculate (a) the time period of the pendulum and (b) the value of acceleration due to gravity at the place of experiment, correct to two significant figures.