Make static object height match the max height of a bouncing ball in any resolution

I am creating a 2D game where a ball is bounced on a paddle. The paddle can be moved to make the ball move around to hit static objects in the air.

ASCII art:

 * => objects to hit
 o => bouncing ball
 ~~~ => paddle

 _______________________
 |                     |
 |       *      o    * | <--- height = 300 in default unity resolution
 |                     |
 |                     |
 |                     |
 |      ~~~~~~         |
 |_____________________|

I want the height of the static objects to match the max height of the bouncing ball. I had this working for the default resolution in Unity, but when I created a new resolution for a web project, the static objects were much lower that the bouncing ball height.

I set the static object heights with:

 // set in inspector - currently 300
 public float height;

 void Start () {
     // set static object at random x value
     Vector2 v = Camera.main.ScreenToWorldPoint(new Vector2(Random.Range (0, Screen.width), height));
     transform.position = new Vector3(v.x, v.y, -1);
 }

I set the bouncing ball with:

 // set in inspector - currently 7
 public float velocity;

 void OnCollisionEnter2D(Collision2D other) {
     // set velocity when ball hits paddle
     if(other.gameObject.name == "paddle") {
         GetComponent<Rigidbody2D>().velocity = new Vector2(0,velocity);
     }
 }

I want to create this for Android. The static objects on my Android phone are set so low they cannot even be hit by the ball:

ASCII art:

 _______________________
 |                     |
 |              o      |
 |                     |
 |                     |
 |                     |
 |      ~~~~~~         |
 |__*____________*_____| <--- height = 300 in android resolution

How can I make the static objects’ heights always match the max height of the bouncing ball? A static number from the inspector is obviously not working. Do I need to get it at run time? Is there an easy way to know that?