How develop reaction when object colllide with another

Questions & Answers
1

How can I develop a reaction when I have an object in moviment by a Force and when it collide with a wall it receive an reaction from the wall and go back with a specific force.

2

Well if i understand ur question correctly u should make a box collider so u can trigger a script that moves ur character back from that position. So basically ull need a cube that has a box collider and the check box for is trigger is checked. Then ull need to make a script that entails the following code(c# is what i use)

using UnityEngine;
using System.Collections;

public class cameraTransistion : MonoBehaviour {
private Transform currentTarget = null;
public Transform player;

void OnTriggerEnter(Collider col)
	{
		if(col.tag == "trigger")
		{
			
			currentTarget = col.transform;
			Debug.Log("Enter");
		}
        }

void Update () {
		if(currentTarget != null)
		{
              player.Translate(1f,1f,1f);
                currentTarget = null;
		}

}

now that should work and u can alter it to ur liking but thats base logic