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bobbym
2013-02-20 22:32:34

Hi;

Those are two parametric equations. We called them that becuse they are both expressed in terms of t.

To graph them in that form you will need a parametric plotter.

sushanta1991
2013-02-20 17:19:54

helllo

velocity is 10 m/s

at 10 m/s it travels approximately 489 m before touching the ground, and this is quite a large distance (non practical )

I think there is no drag , that is why the length of projectile is so long.

Could you help me inserting drag in this formula
x = vt cos ?
y = vt sin ? - ½ g t²

here you can find some formula for drag, http://en.wikipedia.org/wiki/Drag_%28physics%29

and let me tell you i am little dumb in mathematics
Thanks

EDIT : I want to draw the path of projectile.

bobbym
2013-02-20 13:57:06

Hi;

with a initial velocity of 10

10 what?

angle it goes to 489 m

Maximum height? Distance? Arc length? 489 m of what?

sushanta1991
2013-02-20 00:22:01

sorry for reviving this thread again smile

here in this formula
x = vt cos ?
y = vt sin ? - ½ g t²

v (velocity) is the initial velocity or a constant velocity ? will velocity changes with time ? or it remains constant ?

In my last post i ask this.
here is the projectile i get using this formula http://imgur.com/axCKwsP

Don't you guys think for 60* angle this is Quite a large projectile ?
with a initial velocity of 10 and 60* angle it goes to 489 m, let me tell you i am decreasing the initial velocity and increasing time by 0.1 at each step.
I dont know i am doing it in right way or not
can any one suggest me any thing ?

sushanta
2013-02-19 05:52:27

sorry for reviving this thread again

here in this formula
x = vt cos θ
y = vt sin θ - ½ g t²

v (velocity) is the initial velocity or a constant velocity ? will velocity changes with time ? or it remains constant ?

bobbym
2011-08-30 03:06:12

Hi roi187;

Your are welcome and welcome to the forum!

roi187
2011-08-30 03:04:47

#### bobbym wrote:

Hi;

To get rid of the 1 / 2 you multiply by 2, because 2 * 1 / 2 = 1

OK I understand now. Thank you very much!

bobbym
2011-08-30 02:52:26

Hi;

To get rid of the 1 / 2 you multiply by 2, because 2 * 1 / 2 = 1

roi187
2011-08-30 02:46:26

#### bobbym wrote:

Hi;

I don't get why 499.6 was divided into 1/2

Both sides were multiplied by -2

This isn't clear to me a bit; why we multiplied both sides by 2? Is it because we had two T variables there has a coefficient of 2? Sorry, my algebra is really that rusted.

bobbym
2011-08-30 02:39:19

Hi;

I don't get why 499.6 was divided into 1/2

Both sides were multiplied by -2 and some rounding was done

-499.6 * -2 ≈ 999

Then both sides were divided by 9.81 and some rounding done again to get.

100 = t^2

roi187
2011-08-30 01:55:17

#### MathsIsFun wrote:

300 = vt (0.5)
20 = vt (0.866) - ½ g t²

the first equation gives us: vt = 300 / 0.5 = 600

put that into the second equation: 20 = 600 x 0.866 - ½ g t²
rearrange: 20 - 600 x 0.866 = - ½ g t²
simplify: 499.6 = ½ g t²
simplify: 999 = g t²
simplify: 999 = t²
solve: t = ± 10 seconds

Hi, sorry for reviving an ANCIENT thread... I have problems understanding the processes done in this equation.
I don't get why 499.6 was divided into 1/2 and g value is omitted? And lastly, how did sqrt 999 became 9.999 or 10?

Once again I am sorry, but once I get all the answers It'll help me tons.

feral
2007-02-03 11:58:02

hey there, sorry for bumbing an old thread:

I have the following values in my 3d world:

- my current x & y angle
- the distance in meters to the target
- the height offset in meters
- the velocity of the projectile m/s

I need to calculate the angle y offset I need to add to my current angle y so that the missile will hit the target.

I have tried to make a formula but im not good at maths, Im getting confused with the above formulas too because they have t (time), but since my projectile hasn't been fired i won't have time.

Thanks for any help!

chilton tigers
2006-05-19 11:43:31

can i play?>?>?>

chilton tigers
2006-05-19 11:42:22

any one from chilton wis.

raffy
2005-10-09 21:01:01

Thanks guys for all your help. The equations work and I will post a link when the game is launched.