Question

On planet Xerox,which is a close copy of earth,a pendulum that is 1metre long completes one swing in 2 seconds. What would the frequency of this pendulum be if it were only 25 cm long?

Answer 1

time period is directly proportional to root of
length of string
so
now lenth of string is 100 cm
so √L = 10 cm
and T = 2 sec
now L = 25 cm
√L = 5 cm
as
√L is decreased by a factor of 2
then T will also be decreased by a factor of 2
so now new time period will be 1 sec
but this is not answer actually they asked for frequency which is actually 1/T and that is also 1/1 = 1 hertz