adding speed make the ball bounce

okay so I'm using this script for my ball to move with the accelerometer but when I add the speed it starts to bounce like crazy to be specific when I add "transform.Translate" line that happens I'm still new to this any help will appreciate it

 using UnityEngine;
 using System.Collections;
 
 public class Accelerometer : MonoBehaviour 
 {
     public float speed = 5.0F;
     public bool isflat = true;
     private Rigidbody rb;
 
     void Start()
 
     {
         rb = GetComponent<Rigidbody> ();
     }
 
     void Update()
 
     {
         Vector3 tilt = Input.acceleration;
     
         if (isflat)
             tilt = Quaternion.Euler (90, 0, 0) * tilt;
 
         rb.AddForce(tilt);
         transform.Translate(tilt * speed * Time.deltaTime);
     }
 }