Collision work on pc emulator but not on android device

I have 2 objects with colliders. the sphere object("ball") should collide with the mesh("goal"):

• sphere collider

• mesh collider

they both non-kimetric.

i use the next code:

  function OnCollisionEnter(theCollision : Collision){
         if(theCollision.gameObject.name == "goal" )
         {
             (tm.GetComponent(TextMesh) as TextMesh).text  =  "enter1";
             forceAmount.z=-1000;
             rb.AddForce(forceAmount);
         }
     }

the code works perfect in the unity emulator but when i build it to apk file and install on my android tablet its not works.

can anyone help me with this?