if a simple pendulum is dropped in a elevator with a acceleration greater than acceleration due to gravity then what will be its frequency ? We know time period depends on frequency.
Same formula as usual but with the difference that. $$ g\rightarrow g\pm g'$$ where $g'$ is the acceleration of the elevator. The plus sign is used if the two accelerations are in different directions... Thus if elevator free fall then $g-g'=0 $ and the period goes to infinity.