# If you pushed a Dodge Demon out of an airplane...

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**1**CF Senior Member

Thread Starter

**If you pushed a Dodge Demon out of an airplane...**

Would it still complete a quarter mile faster than a Z?

If you let a Demon fall from an airplane from a height of exactly 1/4 mile (and ignoring wind resistance), how long would it take to complete the quarter mile, and would it still be faster than the Z?

My guess is right around 9.1 seconds (s = 1/2at^2), but I'm not a math geek. I assumed acceleration is 9.8 m/sec and that the quarter mile is 402 meters.

I think it'd be cool to run a sub-9.1, then, faster than falling!

If you let a Demon fall from an airplane from a height of exactly 1/4 mile (and ignoring wind resistance), how long would it take to complete the quarter mile, and would it still be faster than the Z?

My guess is right around 9.1 seconds (s = 1/2at^2), but I'm not a math geek. I assumed acceleration is 9.8 m/sec and that the quarter mile is 402 meters.

I think it'd be cool to run a sub-9.1, then, faster than falling!

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**2**2017 GS, M7, 2.5LT

^^^

Yep, 9.06 seconds, Considering you rounded you were right. Would be fun but that sudden stop, not so much!

Now a AA/Fuel dragster does it much quicker because it achieves much more than 1 "g" acceleration.

Yep, 9.06 seconds, Considering you rounded you were right. Would be fun but that sudden stop, not so much!

Now a AA/Fuel dragster does it much quicker because it achieves much more than 1 "g" acceleration.

*Last edited by JerryU; 07-20-2017 at 01:13 PM.*

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**3**CF Senior Member

Thread Starter

A jet car might be more linear!

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**4**Anyway, the car falling from an airplane would have a lot of drag.

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**5**2017 GS, M7, 2.5LT

^^^

More like 8 "gs" off the line and an average of 4 "gs" for the quarter. Just before the traps expect 10,000 hp and looking at the tires at super slomo may well be still over a "g."

More like 8 "gs" off the line and an average of 4 "gs" for the quarter. Just before the traps expect 10,000 hp and looking at the tires at super slomo may well be still over a "g."

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**6**
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**7**If you let a Demon fall from an airplane from a height of exactly 1/4 mile (and ignoring wind resistance), how long would it take to complete the quarter mile, and would it still be faster than the Z?

My guess is right around 9.1 seconds (s = 1/2at^2), but I'm not a math geek. I assumed acceleration is 9.8 m/sec and that the quarter mile is 402 meters.

I think it'd be cool to run a sub-9.1, then, faster than falling!

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**8**CF Senior Member

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Location: Broomes Island, MD

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If you let a Demon fall from an airplane from a height of exactly 1/4 mile (and ignoring wind resistance), how long would it take to complete the quarter mile, and would it still be faster than the Z?

My guess is right around 9.1 seconds (s = 1/2at^2), but I'm not a math geek. I assumed acceleration is 9.8 m/sec and that the quarter mile is 402 meters.

I think it'd be cool to run a sub-9.1, then, faster than falling!

Any aircraft large enough to ferry the Demon to altitude would be going in excess of 100 mph on jump run. All that forward speed has to transfer into vertical speed, which makes the trajectory an arc, thus it has longer to travel than only 1/4 mile. And how close to terminal velocity would it get by the time it hit the ground? Even a hovering helo would alter the math because of the downforce of the wind generated.

I certainly don't have the math to figure it out, but I do know how things behave in free fall.

Maybe if it was pushed off a cliff (or platform) that was 1/4 mi. high in a vacuum?

*Last edited by owc6; 07-20-2017 at 01:43 PM.*

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**9**Even if you ignored wind resistance, which you can't, you have to factor in forward speed of the aircraft.

Any aircraft large enough to ferry the Demon to altitude would be going in excess of 100 mph on jump run. All that forward speed has to transfer into vertical speed, which makes the trajectory an arc, thus it has longer to travel than only 1/4 mile. And how close to terminal velocity would it get by the time it hit the ground? Even a hovering helo would alter the math because of the downforce of the wind generated.

I certainly don't have the math to figure it out, but I do know how things behave in free fall.

Maybe if it was pushed off a cliff (or platform) that was 1/4 mi. high in a vacuum?

Any aircraft large enough to ferry the Demon to altitude would be going in excess of 100 mph on jump run. All that forward speed has to transfer into vertical speed, which makes the trajectory an arc, thus it has longer to travel than only 1/4 mile. And how close to terminal velocity would it get by the time it hit the ground? Even a hovering helo would alter the math because of the downforce of the wind generated.

I certainly don't have the math to figure it out, but I do know how things behave in free fall.

Maybe if it was pushed off a cliff (or platform) that was 1/4 mi. high in a vacuum?

There's a whole clusterfuck of lift/drag stuff to consider though.

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**10**CF Senior Member

Any aircraft large enough to ferry the Demon to altitude would be going in excess of 100 mph on jump run. All that forward speed has to transfer into vertical speed, which makes the trajectory an arc, thus it has longer to travel than only 1/4 mile. And how close to terminal velocity would it get by the time it hit the ground? Even a hovering helo would alter the math because of the downforce of the wind generated.

I certainly don't have the math to figure it out, but I do know how things behave in free fall.

Maybe if it was pushed off a cliff (or platform) that was 1/4 mi. high in a vacuum?

The time for the Demon to do the "vertical quarter mile" would be the same independent of the speed of the airplane it was dropped from. The component of horizontal speed would be added to the vertical acceleration and the path of the demon would be curve rather than straight down. At the point of impact, the total speed would be greater, but the vertical velocity would be the same. I think. But I learned long ago not to believe everything I think

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**11**CF Senior Member

Any aircraft large enough to ferry the Demon to altitude would be going in excess of 100 mph on jump run. All that forward speed has to transfer into vertical speed, which makes the trajectory an arc, thus it has longer to travel than only 1/4 mile. And how close to terminal velocity would it get by the time it hit the ground? Even a hovering helo would alter the math because of the downforce of the wind generated.

I certainly don't have the math to figure it out, but I do know how things behave in free fall.

Maybe if it was pushed off a cliff (or platform) that was 1/4 mi. high in a vacuum?

*Last edited by Apocolips; 07-20-2017 at 03:33 PM.*

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**12**CF Senior Member

The time for the Demon to do the "vertical quarter mile" would be the same independent of the speed of the airplane it was dropped from. The component of horizontal speed would be added to the vertical acceleration and the path of the demon would be curve rather than straight down. At the point of impact, the total speed would be greater, but the vertical velocity would be the same. I think. But I learned long ago not to believe everything I think

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**13**CF Senior Member

Thread Starter

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**14**CF Senior Member

Wait, are you saying that a 7.62mm rifle, fired straight down from an altitude of say 1330’, and a bullet of the same size dropped at the same time would hit the ground at the same time???

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**15**CF Senior Member

Ha. Of course not. That's why I used the phrase "horizontal velocity". Gravity is a constant and doesn't change with the an object's speed. A bullet fired horizontally from a rifle at let's say 10', and a bullet dropped vertically from 10' at the same time as the rifle is fired, will both hit the ground at the same time.

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**18**CF Senior Member

Thread Starter

It's the old "If a monkey is hanging from a tree and you fire a shot at the exact time it lets go, you still hit it because the monkey falls at the same rate as the bullet" problem.

The one factor I can't account for in my head is the gyroscopic force. There's some resistance to the bullet nosing over, and it can "steal" energy from the bullet's rotation. But that just prevents the bullet from changing angles, and doesn't affect it's drop, so maybe it's not a factor at all.

Remember too, the original post said "ignoring wind resistance" because it gets too complicated with drag. But it doesn't matter for the bullet drop version.

*Last edited by davepl; 07-20-2017 at 06:58 PM.*

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**19**2017 GS, M7, 2.5LT

However since air flow is now done with modeling it could probably be done!