## Code Name: Steel Rain a WMD for paintball

### #16

Posted 16 July 2007 - 08:33 PM

### #17

Posted 16 July 2007 - 08:49 PM

### #18

Posted 16 July 2007 - 09:45 PM

--Ruckus

### #19

Posted 16 July 2007 - 09:47 PM

That equation only applies where the object is in true free-fall... Only one force acting on the object, gravity. Here, we're going to have wind resistance, so we get a terminal velocity, meaning that as the object falls faster and faster, the force of drag will increase until it equals the force of gravity, and the object will then stop accelerating and fall at a constant velocity, except where changes in its shape, air temperature, and other disturbances may temporarily alter the balance of gravity versus drag. These would not, of course, be significant in the application we are talking about.

Bottom line: If you want to find out the terminal velocity of one of those bladders, you're either going to have to catch one coming down with a radar gun or do some REALLY, REALLY complex calculus. This is exactly the type of thing ENIAC was invented for in WWII, calculating trajectories for artillery shells, and there is a reason they went to the trouble of building a computer for it. It's HARD.

### #20

Posted 16 July 2007 - 10:50 PM

### #21

Posted 17 July 2007 - 10:12 AM

Nemidaelius, on Jul 16 2007, 09:47 PM, said:

That equation only applies where the object is in true free-fall... Only one force acting on the object, gravity. Here, we're going to have wind resistance, so we get a terminal velocity, meaning that as the object falls faster and faster, the force of drag will increase until it equals the force of gravity, and the object will then stop accelerating and fall at a constant velocity, except where changes in its shape, air temperature, and other disturbances may temporarily alter the balance of gravity versus drag. These would not, of course, be significant in the application we are talking about.

Bottom line: If you want to find out the terminal velocity of one of those bladders, you're either going to have to catch one coming down with a radar gun or do some REALLY, REALLY complex calculus. This is exactly the type of thing ENIAC was invented for in WWII, calculating trajectories for artillery shells, and there is a reason they went to the trouble of building a computer for it. It's HARD.

Here's an idea why dont you crunch the numbers first:

Equation 1: Vf=V1 +2at and Equation 2:d=V1(t) +.5at^2

V1=Initial velocity...............V1=0 (If you start at the top of the arc then the velocity is zero)

a=acceleration....................a=9.81 (this is a constant if you have a problem with this talk to Sir Isaac Newton)

t=time................................t= I dont know so I will use the 2nd equation to find it-------> Aprox. 3.52sec Up and 3.52 Down

d=distance.........................d=60.96 m

Vf=final velocity.................Vf= Now this is what we really want to know.........69.167meters/sec

That means that no matter what this thing will not move faster than 226.92585 Feet per second.

So there is no way that if what you are "raining" down is paintballs that this contraption will hurt you more than a standard paintball.

*Note: Keep in mind what Nemidaelius said, this is not an exact number... the actual number might be considerably less. I say your biggest problem in this case would not be how fast things are coming down but, how do you shoot something 200ft in the air and get it to hit your target?

This post has been edited by **Sparky101**: 17 July 2007 - 10:14 AM

### #22

Posted 17 July 2007 - 12:39 PM

### #23

Posted 17 July 2007 - 05:19 PM

### #24

Posted 17 July 2007 - 05:30 PM

not very practical

My feedback

### #25

Posted 17 July 2007 - 07:19 PM

### #26

Posted 17 July 2007 - 08:12 PM

HeadshotPhantom, on Jul 17 2007, 12:39 PM, said:

I was using paintballs as a easier mode of comparison. If you are that worried about the force (force=mass*acceleration/surface area) but I will leave that one for you.

Lets just say for argument's sake that the grenade has too great a force a 200ft, then you have two options. One shoot somthing smaller (Paintballs) or have the gun shoot to a lower altitude (150ft). Im just trying to solve problems

Work and it will change the game of paintball as we know it.

### #27

Posted 17 July 2007 - 08:32 PM

### #28

Posted 17 July 2007 - 08:39 PM

Sparky101, on Jul 17 2007, 12:12 PM, said:

Nemidaelius, on Jul 16 2007, 09:47 PM, said:

That equation only applies where the object is in true free-fall... Only one force acting on the object, gravity. Here, we're going to have wind resistance, so we get a terminal velocity, meaning that as the object falls faster and faster, the force of drag will increase until it equals the force of gravity, and the object will then stop accelerating and fall at a constant velocity, except where changes in its shape, air temperature, and other disturbances may temporarily alter the balance of gravity versus drag. These would not, of course, be significant in the application we are talking about.

Bottom line: If you want to find out the terminal velocity of one of those bladders, you're either going to have to catch one coming down with a radar gun or do some REALLY, REALLY complex calculus. This is exactly the type of thing ENIAC was invented for in WWII, calculating trajectories for artillery shells, and there is a reason they went to the trouble of building a computer for it. It's HARD.

Here's an idea why dont you crunch the numbers first:

Equation 1: Vf=V1 +2at and Equation 2:d=V1(t) +.5at^2

V1=Initial velocity...............V1=0 (If you start at the top of the arc then the velocity is zero)

a=acceleration....................a=9.81 (this is a constant if you have a problem with this talk to Sir Isaac Newton)

t=time................................t= I dont know so I will use the 2nd equation to find it-------> Aprox. 3.52sec Up and 3.52 Down

d=distance.........................d=60.96 m

Vf=final velocity.................Vf= Now this is what we really want to know.........69.167meters/sec

That means that no matter what this thing will not move faster than 226.92585 Feet per second.

So there is no way that if what you are "raining" down is paintballs that this contraption will hurt you more than a standard paintball.

*Note: Keep in mind what Nemidaelius said, this is not an exact number... the actual number might be considerably less. I say your biggest problem in this case would not be how fast things are coming down but, how do you shoot something 200ft in the air and get it to hit your target?

Your calculations aren't fool proof, mind you. You can't instantly assume that the acceleration of the being (grenade) will be 9.8. By doing so you are taking out factors of wind, temperature, and CO2 or HPA emissions. Nothing can be for certain, really. Just like you can't tell me that my next shot will be 260FPS. It might be 261. There are different variables that take into affect. A gust of wind might slow down the acceleration. Even so...your calculations are assuming that something is dead weight in a vacuum. A launched projectile does not simply "Fall" out of the sky. It follows a trajectory...slowly losing speed due to other variables along the way. Not trying to say you are a bad mathematician...but mathematics can't solve the reason why alone. You need to apply some physics and some logical mood on angles. Ah...but that's all Trigonometry and Calculus. Neither of which are my strong suit.

--Ruckus

### #29

Posted 17 July 2007 - 10:35 PM

Ruckus Fox, on Jul 17 2007, 08:39 PM, said:

Sparky101, on Jul 17 2007, 12:12 PM, said:

Nemidaelius, on Jul 16 2007, 09:47 PM, said:

That equation only applies where the object is in true free-fall... Only one force acting on the object, gravity. Here, we're going to have wind resistance, so we get a terminal velocity, meaning that as the object falls faster and faster, the force of drag will increase until it equals the force of gravity, and the object will then stop accelerating and fall at a constant velocity, except where changes in its shape, air temperature, and other disturbances may temporarily alter the balance of gravity versus drag. These would not, of course, be significant in the application we are talking about.

Bottom line: If you want to find out the terminal velocity of one of those bladders, you're either going to have to catch one coming down with a radar gun or do some REALLY, REALLY complex calculus. This is exactly the type of thing ENIAC was invented for in WWII, calculating trajectories for artillery shells, and there is a reason they went to the trouble of building a computer for it. It's HARD.

Here's an idea why dont you crunch the numbers first:

Equation 1: Vf=V1 +2at and Equation 2:d=V1(t) +.5at^2

V1=Initial velocity...............V1=0 (If you start at the top of the arc then the velocity is zero)

a=acceleration....................a=9.81 (this is a constant if you have a problem with this talk to Sir Isaac Newton)

t=time................................t= I dont know so I will use the 2nd equation to find it-------> Aprox. 3.52sec Up and 3.52 Down

d=distance.........................d=60.96 m

Vf=final velocity.................Vf= Now this is what we really want to know.........69.167meters/sec

That means that no matter what this thing will not move faster than 226.92585 Feet per second.

So there is no way that if what you are "raining" down is paintballs that this contraption will hurt you more than a standard paintball.

*Note: Keep in mind what Nemidaelius said, this is not an exact number... the actual number might be considerably less. I say your biggest problem in this case would not be how fast things are coming down but, how do you shoot something 200ft in the air and get it to hit your target?

Your calculations aren't fool proof, mind you. You can't instantly assume that the acceleration of the being (grenade) will be 9.8. By doing so you are taking out factors of wind, temperature, and CO2 or HPA emissions. Nothing can be for certain, really. Just like you can't tell me that my next shot will be 260FPS. It might be 261. There are different variables that take into affect. A gust of wind might slow down the acceleration. Even so...your calculations are assuming that something is dead weight in a vacuum. A launched projectile does not simply "Fall" out of the sky. It follows a trajectory...slowly losing speed due to other variables along the way. Not trying to say you are a bad mathematician...but mathematics can't solve the reason why alone. You need to apply some physics and some logical mood on angles. Ah...but that's all Trigonometry and Calculus. Neither of which are my strong suit.

--Ruckus

OK this is not complicated, I did not tell you where it would land or how many times it turned over and over before it hit or did not hit the target. All I said was at the maximum a paint grenade falling from 200ft would travel at a maximum speed of 227 feet per second (give or take 10 feet per second if it makes you feel better). This is basic physics, if you want a tolerance you need test and some knowledge of statistics. If you are concerned with the of air pressure or the temperature or any of this you are giving air way to much credit, with a fall time of 3 seconds the percentage of velocity change is so small(no more than 5%) that it is not even worth looking into, in fact any large differences to the velocity is most likely human error (We are not perfect). I have both Trigonometry and Calculus under my belt and I am telling you, you are making this way more complicated than it should be.

As for gravity it accelerates everything at 9.81 meters per second per second. No mater how much you dont want it to, if you step on a scale and you weigh 130 pounds and you step of and back on you will still weigh a 130 pounds (Thanks to gravity trying to accelerate your body at the same rate).

If you are not sure about something phrase it as a question not a statement, if any one is interested in any of this write to me personally, this tread is not about science its about "Code Name: Steel Rain"

### #30

Posted 17 July 2007 - 10:49 PM