Game-- about collision detection(J2ME)

[c_nick]

How can let one object collision with line (use J2ME)??
Eg: Have a line which slope is 2 and the object (ball ) sleep is 5 and then fly toward to that line. how can let it reflect when the object (ball) collision with line??

[jherber]

try to visualize a line perpendicular to your initial line that passes through the center of your ball.

the slope of this line is the reciprical of your initial line:
http://www.purplemath.com/modules/slope2.htm

now you have two linear equations and can look at the intersection point.  

when the distance between the intersection point and the center of the ball is <= radius of the ball, you have a collision.