years) time period = 1.419 sec
The time period (T) of a simple pendulum is directly proportional to the square root of its length (l).
T is directly proportional to
T=2 ft*sqrt(l/g)
T = 2 * pi * sqrt(0.5 / 9.8)
T = 2 * pi * 0.2259
T = 1.419 seconds.
T = 2 * pi * sqrt (l / g)
T = 2 * pi * sqrt(0.5 / 9.81)
T = 2 * pi * 0.22576
T = 1.4185 seconds