A freely falling body takes 2 seconds to reach the ground on a planet, when it is dropped from a height of 8m. If the period of a simple pendulum is π seconds on the planet. The length of a pendulum is ( in centi meter)

A freely falling body,u=0, then height h from where body is dropped is        h=12gt2  , given h=8, g is acceleration due to gravity        8=12gp22,         gp is acceleration due to gravity on planet   ⇒gp=4             ,substitute in time period of simple pendulum       T=2πlgp      , given Time period T=π        π=2πl4 ⇒ l=1 m=100 centi meter.