update

src/main/java/PingPong/GamePanel.java

@@ -43,7 +43,16 @@ public class GamePanel extends JPanel implements Runnable {
             if(collisionChecker.didTouchTopOrBottomEdge(ball.y, FRAME_HEIGHT-BALL_DIAMETER)) {
                 ball.setYDirection(-ball.yVelocity);
             }
-
+        if(collisionChecker.didTouchPaddle(ball, new Rectangle(paddle_1.x, paddle_1.y1, paddle_1.width, paddle_1.height))) {
+            ball.xVelocity = Math.abs(ball.xVelocity);
+            ball.xVelocity++;       // increasing ball's speed!
+            if (ball.yVelocity > 0)
+                ball.yVelocity++;
+            else
+                ball.yVelocity--;
+            ball.setXDirection(ball.xVelocity);
+            ball.setYDirection(ball.yVelocity);
+        }
     }