The length of a second pendulum is 100 cm whose time period is 1.4 sec.
Step 1: Given data
We know a second pendulum is a pendulum whose time period is 2 sec.
Thus, the time period of seconds pendulum
Length of a seconds pendulum is
Time period of a simple pendulum
Length of a simple pendulum
Step 2: Relationship between time period and length
We know that the time period is directly proportional to the square root of the length
Hence it can be written as,
Step 3: Calculate the length of a simple pendulum (L2)
Hence, the length of a simple pendulum is 49 cm.