Given that the time period of the pendulum is T = 2 s
Let the length of the pendulum be L.
The new length of the pendulum is 2L
The relation between length and time period is
Here, g = 9.8 m/s^2 is the acceleration due to gravity.
The length will be
The new length will be
The new length will be 1.988 m
The new time period will be
Thus, the new time period is 2.83 s