I need to get the x/y values of a fired projectile given the angle of the initial power, and air resistance.
The formulas I have are
$$X=V_o \cos \theta t$$
$$V_y=V_o \sin \theta -gt$$
$$Y=V_o \sin \theta t-(1/2)gt^2$$
To calculate the initial velocity $V_o$, I did
$E$ = power with which the ball was fired, $m$ = mass of ball
What I need is how to add air resistance to this equation
Besides, are my equations correct?