## Heights & Numbers

### November 19, 2009

The video i posted earlier today reminded me of a little curiosity i have with heights and numbers. Or more, whenever i hear of a building’s height i think about how long it would take something to reach the ground when thrown off the top or dropped off of the top of the building. I usually go ahead to calculate the answers using some of the high-school and Physics 101 class from university.

Follow the jump to find out how long it would take you to hit the ground if you throw yourself off Burj Dubai, Burj Al-Hamra, Kuwait Towers or The World Trade Center!

The equations are simple:

S= ut+ ½at²

or in lay man’s terms Distance = Initial Speed x time + Half X Acceleration (Gravity) x time^squared…And

Speed = Acceleration X Time

**So for Burj Dubai i calculated it as follows:**

*Burj Dubai has a height of 818m;*

*818 = (0xt) + (½ x 9.81(Gravity) x t²)
t≈ √((818 x 2) ÷ 9.81)≈ 12.91 seconds*

*speed = acceleration x time
= 9.81m/s² x 12.91s
= 126.7 m/s (456 kph)
*

I used the approximately equals sign(≈) because there would be wind resistance and the gravity would be different at that elevation and geographical location but the real result should be something similar or at least a little close.

I have done this for fun before for Burj AlHamra, The World Trade Center and many others…

**Burj AlHamra:** 405m, 9.1s, 89m/s (321 kph)

**Kuwait Towers:** 150m, 5.5s, 54.3m/s (195 kph)

**World Trade Center:** 417m, 9.2s, 90.5m/s (326 kph)

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This also got me think about what would be the appropriate height for someone suicidal to jump from, so he (or she) would not regret their suicide before they hit the ground.

But i don’t have any numbers for that. :P

I think i started these calculations around the time i heard about a novel about an architect who struggles in life while designing and constructing the tallest building in the world and at the end commits suicide by throwing himself off, it’s sad. And unfortunately i don’t know the name of Author or the book, I Googled it a lot and i still cant find it. I found the subject really interesting and still want to know what drove him to his limit.

how tall was the twin trade tower’s before they fell and dude imagine driving at 456 kph then imagine it falling splat

but i read that u lose conciseness before hitting the ground :/

i don’t know anyways man nice blog and cool info keep up the good work :)