Object coordinates not updating as expected

I'm having an issue with a prefab I'm instantiating in my script. What I'm attempting to do is simulate the physics behind the projectile motion of a cannonball. I have the following script attached to my prefab:

 using UnityEngine;
 using System.Collections;

 public class ShootPhysics : MonoBehaviour {

     // vectors & angles to be calculated
     private float fx = 0f;
     private float fy = 0f;
     private float angle;

     // forces acting upon object
     private float gravity = 9.8f;
     private float force = 1.2f;

     // new distance & vector variables
     private float dis_x = 0f;
     private float dis_y = 0f;

     // Script & CannonBall transform
     private CannonPhysics cannon_angle;

     void Start() {
         cannon_angle = GameObject.FindWithTag("Gun").GetComponent<CannonPhysics>();
         angle = cannon_angle.getAngle ();
         fx = Mathf.Round (force * Mathf.Cos(Mathf.Deg2Rad * angle));
         fy = Mathf.Round (force * Mathf.Sin(Mathf.Deg2Rad * angle));
     }

     void FixedUpdate() {
         dis_x = (float)(fx * Time.timeSinceLevelLoad);
         dis_y = (float)(fy + Time.timeSinceLevelLoad + (0.5) * (-gravity) * Time.timeSinceLevelLoad * Time.timeSinceLevelLoad);
         Debug.Log (dis_x+", "+dis_y);
         gameObject.transform.Translate (new Vector2(dis_x, dis_y));
     }

 }

And the prefab will be instantiated from the following script:

 using UnityEngine;
 using System.Collections;

 public class CannonPhysics : MonoBehaviour {
     
     // This will be our script to rotate our cannon
     private float angle = 0f;
     
     // cannonball object
     public Transform FirePoint;
     GameObject cannon = null;
     
     void Update() {
         if(Input.GetKey(KeyCode.UpArrow)) {
             angle = angle + 1;
         }
         if(Input.GetKey(KeyCode.DownArrow)) {
             angle = angle - 1;
         }
         
         // update cannon angle
         transform.rotation = Quaternion.Euler (new Vector3(0, 0, angle));
         
         if(Input.GetMouseButtonDown(0)) {
             CreateCannon();
         }
     }
     
     public float getAngle() {
         return angle;
     }
     
     private void CreateCannon() {
         cannon = Instantiate (Resources.Load("Prefabs/CannonBall"), FirePoint.position, FirePoint.rotation) as GameObject;
         Destroy (cannon, 3f);
     }
     
 }

The object gets instantiated as it should, and the object is destroyed after 3 seconds as it should, however the object x and y position do not change at all, and are not what i should expect them to be. Let me give you an example:

These are the x and y coordinates i should expect which i have displaying in the console.

However these are the actual coordinates displayed in Unities inspector:

What's strange too, is that these coordinates will not change for each object, they will literally stay the same, even after the object has been destroyed. Can anyone explain why this is happening? And perhaps offer a solution?