## Thread: iPhone 4 Survives 13,500 Foot Fall - Much To The Surprise Of The Owner

1. Originally Posted by cookbenj
lol, and the cost to repair it? let me guess? a cost of a new iphone, to me from that picture it did not survived its barley usable... i mean would you use your iphone like that? that is definitely broken
\$20 if you buy the parts on ebay and do it yourself, if as it appears its just the screen and back cover damaged.

2. Wonder if the Otterbox case would have survived this :/

3. Originally Posted by Orby
That phone hit the earth's surface with (it's been far too long since I took physics) .137 kg * 9.8 (m/s^2)* 4,114.8 m = 5.524 kJ of kinetic energy and it's still functioning?

DANG. That's roughly equivalent to a 100 kg man (~220 lbs) sitting on the phone at 38.5 MPH from about a foot above the chair. I can vouch from personal experience that doesn't end too well usually. Quite impressive the thing lived.
That's potential energy, just saying

Originally Posted by buggsy2
This is a useless and meaningless calculation since as another commenter noted, the iPhone reached its terminal velocity long before it hit.
Not useless because he uses the acceleration due to gravity, not the velocity of the phone as it is falling. Even if the phone reaches its maximum velocity the acceleration is still applied to it, it just doesn't accelerate because of drag.

4. Am i missing something?
Originally Posted by Sk3pticalKiller
That's potential energy, just saying

Not useless because he uses the acceleration due to gravity, not the velocity of the phone as it is falling. Even if the phone reaches its maximum velocity the acceleration is still applied to it, it just doesn't accelerate because of drag.
Actually it's kinetic energy since all of the initial potential energy from the beginning of the fall has now converted to kinetic energy.

And, maybe i'm missing something here but why do you people talk about terminal velocity? how do you know it's reached before that distance, that actually depends on the air resistance in that moment and for each height. If the object is subject to acceleration by gravity, that means it's velocity augments until air resistance and other drag forces have the same magnitude as gravity, so the sum of forces would be 0 and so acceleration would be 0 too and velocity would be constant (terminal velocity). So, am i missing something?

5. Originally Posted by DBS2009
Actually it's kinetic energy since all of the initial potential energy from the beginning of the fall has now converted to kinetic energy.

And, maybe i'm missing something here but why do you people talk about terminal velocity? how do you know it's reached before that distance, that actually depends on the air resistance in that moment and for each height. If the object is subject to acceleration by gravity, that means it's velocity augments until air resistance and other drag forces have the same magnitude as gravity, so the sum of forces would be 0 and so acceleration would be 0 too and velocity would be constant (terminal velocity). So, am i missing something?
His equation is the equation for Potential Energy, kinetic energy is E = 1/2*m*V^2.
If it was a frictionless air then the final velocity would be just before the phone hits the ground, but because of drag the force due to gravity is canceled (acceleration due to gravity never goes to 0 but is countered by the acceleration due to drag)
Air resistance is drag. So when drag equals force due to gravity there is no NET acceleration, therefore the velocity is constant (the iphone moves at the same speed); the phone reaches its final velocity before hitting the ground, its just hard to say what the speed is and when it reaches it.

6. This thread is alive. Lol. I'll add that it seems likely most object would reach terminal velocity from 13.5k feet. Also, very plausible that the phone is still operable and repairable if it impacted, even concrete, at the right angle. Its a solid phone. I think the real argument here is only upon the many interpretations of the word "survived".

Also I have an iPhone 4, and I went swimming with it about a week and a half ago. I realized immediately and got out with it dried it off and put it on rice and I'm leaving this post from it today. The only damage I've noticed is the power/sleep button doesn't work. I'd say it survived. Lol.

Also about two years ago, my father had a 3G, swam with it for the better part of half an hour before he realized. Water was in and between the screen, and after taking out the aim and letting it air dry for 3 days it turned on, but was totally inoperable. iOS didn't load, screen was tweaked and flashy and LCD was pretty badly discolored. A lost cause....or so we thought. 3 weeks later, just for poops and grins, I charged it up and it worked perfectly. Screen was still messed up fairly bad. Only two weeks after that however the screen had absolutely no evidence of any damage, bright true colors, and not a pixel stuck or broke. It literally, and miraculously, healed itself. Like it never happened. My step brother used the phone as his own for a year after that.

7. My two and a half cents The survivability of a fall does not depend upon how fast it's going, or the kinetic energy or the rest of the awesome Laws of Physics . Falling did not cause damage. So what causes the damage? How quickly did it stop?

Two extremes: Did it land on concrete? Did it land on a large balloon filled with air?

Where it lost it's energy provided a level of cushion that's nearly impossible to calculate

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