Fig. 13.4 shows an oscillating pendulum.
Time taken by the bob to move from A to C is t 1 and from C to O is t 2 . The time period of this simple pendulum is
Time period is time taken by the pendulum to complete one oscillation.
one oscillation =
time taken from A to O and O to B is the same.
One oscillation = (A to C) + (C to O) + (O to B) + (O to C) + (C to A)
= (t1 + t2) + (t1 + t2) + (t1 + t2)+ (t1 + t2) = 4(t1 + t2)