Roll-a-Ball enemy ball AI

Hi everyone, well i watched the “roll-a-ball” tutorial and I got a good result after all. Now I’m trying to add some “bad balls”, but I’m getting some problems with the AI. I’m using navmesh to do it, but when the bad ball hits the player nothing happens, it keeps hitting the player but didn’t pushes him.

This is the code of the enemy ball:

using UnityEngine;
using System.Collections;

public class Enemy : MonoBehaviour {

	Transform player;
	NavMeshAgent nav;


	
	void Awake () 
	{
		player = GameObject.FindGameObjectWithTag ("Player").transform;

		nav = GetComponent <NavMeshAgent> ();
	}
	
	
	void Update () 
	{
		nav.SetDestination (player.position);
	}
}

What I’m doing wrong ? :\

Non-rigidbodies do not apply forces to Rigidbodies. Try adding a Kinematic Rigidbody to the bad ball to get a pushing effect. The other option is to get a script with an OnCollisionEnter that applies force in the direction the bad ball is going upon contact.