Help with ballistics formula  TOPIC_SOLVED

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Help with ballistics formula

Postby standardtoaster on Tue Nov 24, 2009 5:40 pm

This deals with my ballistics formula. I found out how to solve for the speed!
As far as I know, this formula does work properly. This formula only works if the surface the object is launched from and is flying over is flat.

= Speed of projectile
= Distance traveled
= Gravity down force
= Angle of the gun

That formula gives me the speed of the object as a scalar, as far as I know.

And this is what a friend had told me about how to get it as a vector

Would I be able to solve for the scalar velocity if I use the first equation as ?
If this helps, here is what he had said:
you'll need first those values for calculations
Angle on which gun is pointing at(or range you want to, but then you'll need to decice wether the gun is in low/high angle)
Speed of projectile(i don't think rockets will be easy to calculate)
and Gravity strength(default = 9.8).

for now, i'll give an example. in this case, a gun firing a bullet in a 100 m/s velocity, 30 degrees angle of launch, and a 10 m/s² gravity acceleration(making it easier for you to understand).

you'll need to determine the range on which the projectile will land on.
sin(30 degrees)*100 = 50 m/s Y velocity at launch.
cos(30 degrees)*100 = 50*(3^0.5) x velocity at launch.
next step is calculating flight time. in this case, (Y velocity / Gravity)*2(because your projectile will fall down too). with the specified conditions, this equals to a 10 second flight time.
now, multiplying the X velocity by the flight time, you get a 500(3^0.5) meter flight distance*
*=Eliminating other factors, like air friction, and making sure the ground is flat.

you'll need lots of math to do that... good luck :lol:
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Joined: Tue Oct 27, 2009 8:08 pm



Re: Help with ballistics formula

Postby standardtoaster on Sat Nov 28, 2009 4:05 am

Come on! I need help with this! If this is of any help have a look at this:
Posts: 7
Joined: Tue Oct 27, 2009 8:08 pm

Re: Help with ballistics formula  TOPIC_SOLVED

Postby standardtoaster on Sun Nov 29, 2009 12:45 am

Success! With the help of my friend who is amazing in calculus and trigonometry, I have done it!(except for air friction)

Solve for . In this case, we will use 100 as D and will be 30°

For clarity, we will switch the position of the variable.

Now that we have the speed as a magnitude, we can finally split it into and . We need to make sure that is always positive, otherwise, it will shoot the projectile downwards.

This means that you can calculate how fast a projectile needs to be moving given the angle of the gun and the distance between the gun and your target. :D These equations will give you the exact velocity it needs to be shot out. It is only exact if you were to shoot the projectile without any air friction. :lol: I'll keep this post updated seeing as most of you aren't that big on ballistics. I hope that this is okay to do. I hope that someone, other than me, will find this helpful.
Posts: 7
Joined: Tue Oct 27, 2009 8:08 pm

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