When you hit your ball into a black hole, it is transported to the exit and ejected at the angle of the exit at a speed directly relational to the speed your ball was going. Choose the Hole → Show Info menu item to see which Black Hole goes to which exit and which direction the ball will come out of the exit. The rim around Black Holes are the same color as their corresponding exits. Hit the ball into the black hole, which will then eject the ball into the cup so you can go to the next hole.