Solving Power of Projectile with Air Resistance

[oghenez]

Homework Statement

I need to get the x/y values of a fired projectile given the angle of the initial firs and the power, with air resistance included

Homework Equations

(@ =theta, Vx=velocity along x-axis,Vy=velocity along y-axis,Vo=initial velocity)
The formula i have is
Vx=VoCos@
X=VoCos@t
Vy=VoSin@-gt
Y=VoSin@t-(1/2)gt^2

The Attempt at a Solution

to calculate the initial velocity Vo
Vo=sqr(2E/m)
where
E = power with which the ball was fired,
m =mass of ball

What i need it how to add air resistance to this equation
Besides, are my equation correct?

 

[oghenez]

please i just need to include air drag into this, please, i have search the forum without success

 

[1994Bhaskar]

IN YOUR FIRST POST SPECIALLY WITH YOUR ATTEMPT TO SOLUTION.YOU ARE TRYING TO APPLY ENERGY CONSERVATION FOR SUCH A CASE WHERE YOU WANT AIR RESISTANCE INCLUDED YET YOU DON'T KNOW THE ENERGY LOST DUE TO IT?
IT IS THUS WRONG.
BY THE WAY FOR AIR DRAG IT'S VERY DIFFICULT TO INCLUDE IT ON EQUATION'S.MANY A TIMES IT IS WRITTEN AS:FORCE DUE TO AIR=KV².
WHERE V IS INSTANTANEOUS VELOCITY OF PARTICLE, K IS A CONSTANT FACTOR DEPENDING UPON VARIOUS THINGS LIKE SHAPE,SPEED OF WIND'S,etc.
YOU MAY INCLUDE THE ABOVE EQUATION BUT BY INTEGRATING IT ALL OVER THE TRAJECTORY.
IF YOU WANT MORE DETAILS POST AGAIN AND I SHALL SHOW YOU THOSE CALCULATIONS!

 

[oghenez]

am trying to simulate the movement of a projectile, but instead of adding initial velocity, i added initial KE, that is the initial with which the ball was fired, so i used
E=0.2mV^2
thus initial velocity V is
Vo=sqrt(2E/m)
the vertical component of the velocity at anytime Vy
Vy=VoSin(theta)-gt
the horizontal velocity Vx is
Vx=VoCos(theta)

The air drag would definitely affect the velocities of the projectile

so the question is, how do i add the air drag in this equation?

 

[1994Bhaskar]

FIRSTLY TRY TO UNDERSTAND TOUR MISTAKE IN ENERGY CONSERVATION.YOU DO NOT KNOW ENERGY LOST DUE TO AIR IN FORM OF HEAT,SOUND,etc.
WELL YES THE AIR DRAG WILL CERTAINLY AFFECT V_x & V_y.just check the attachment as it's difficult for me to type here with math symbols.
BY THE WAY THE ATTACHMENT'S ARE IMAGES GOT USING PRINT SCREEN COMMAND.THEY START FROM 1 TO 5.EACH ARE IN ORDER.DO TRY TO UNDERSTAND.

BEST OF LUCK!