BoomBoom

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class BoomBoom : MonoBehaviour
{
    //How long till the bomb is active after spawning
`   public float m_PrimeTime = 2;
    //How long has the bomb exsisted
    public double m_PreDetTime;
    //The prefab the actually explodes
    public GameObject Explosion;
    //How much force it takes to explode
    public int Impact_Threshold;


    private void OnCollisionEnter(Collision collision)
    {
        //Has the bomb existed for long enough to be primed?  If yes continue
       if (m_PreDetTime >= m_PrimeTime)
        {
            //Is force of impact greater than the Impact_Threshold?  If so continue
            if (collision.relativeVelocity.magnitude > Impact_Threshold)
            {
                //Object is created where the bomb is on impact, this creates the explosion before despawning
                GameObject BoomHolder = Instantiate(Explosion, this.transform.position, this.transform.rotation) as GameObject;
                //Destroy the Bomb
                Destroy(this.gameObject);
                //Destory the BoomHolder after 5 Seconds (Make this slightly longer than your clip)
                Destroy(BoomHolder, 5.0f);
            }
        }
    }

    void Update()
    {
        m_PreDetTime += Time.deltaTime;
    }
}