You will take 5.71 s to reach terminal velocity, and you will have travelled 159 m by then. You will travel the remaining 669 m at constant terminal velocity. This will take you 11.94 s. So the total time you will take is 17.65 seconds.

Let’s break this down step by step.

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1. Known data
- Height of Burj Khalifa: 828 m (to tip)
- Highest occupied floor: ~585 m above ground (we’ll use total height for a “fall from the top” including spire).
- Acceleration due to gravity: ( g \\approx 9.8 \\ \\text{m/s}^2 )
- Air resistance will play a huge role — terminal velocity for a human in belly-down position is about 53 m/s, in head-down up to ~90 m/s, but for an uncontrolled fall, often taken as 55 m/s or so.

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2. Without air resistance
Using ( s = \\frac12 g t^2 ):

[ t = \\sqrt{\\frac{2s}{g}} = \\sqrt{\\frac{2 \\times 828}{9.8}} \\approx \\sqrt{169.0} \\approx 13.0 \\ \\text{s} ]

Speed at impact:
[ v = g t \\approx 9.8 \\times 13.0 \\approx 127.4 \\ \\text{m/s} ]
That’s far above terminal velocity, so air resistance matters a lot.

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3. With air resistance
We need to model velocity over time.
Terminal velocity ( v_t \\approx 53 \\ \\text{m/s} ) for a skydiver belly-down; for a falling person possibly less if not streamlined, but let’s take ( v_t = 53 \\ \\text{m/s} ).

Equation of motion:
[ v