Answer
Time taken will be 13.03 seconds
Work Step by Step
Distance s(t) in feet travelled by a freely falling object is given by the function $s(t)=16t^2$
The height i.e. s(t) of Burj Khalifa is 2717 feet.
Time taken will be-
$s(t)=16t^2$
Step-1: Substitute s(t) in the formula
$2717=16t^2$
Step-2: Divide both sides by 16
$\frac{2717}{16}=t^2$
Step-3: Use the square root property
$±\sqrt \frac{2717}{16}=t$
$± \frac{52.1248}{4}=t$
$± 13.0312=t$
Since time cannot be negative, $t=13.0312$ seconds which is approximately equal to 13.03 seconds.