quick math

ok im working with a graph and im making it so if i click somewere and it makes a ball that ball will go twords another point.
what i have to work with is a function than is like this :

Code:

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create(baseball,xstarting position,ystarting position,x velosity,y velocity)

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i have it so it will get the position of the mouse for position xstarting position , ystarting position and i dont know how to make it so i can give it a velocity that will got twords another position all the time and the other position is moving? and help??

considering time in seconds the position of the ball will be, disregarding attrition

Code:

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        | x = x_initial + v_x * time
pos(t) = |
        | y = y_initial + v_y * time + 9.8 * time^2 / 2

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in 'y' you have to account for the gravity.
Then you have to solve a system of equations. You know the final position (x, y) and the initial position (x, y). 2 variables remain (vx, vy) and 2 equations. Solve the system.