(beginner)unity 5 on collision enter make object visible for a period of time

Hi i am beginner on scripting.

Can you tell me how can i make object renderer enabled for a period of time, if it collide with object name “train”

All I found tutorials is for unity 4.

I am trying to make a warning system for a train pass, when train come, warning lights will be visible for some seconds, then after invisible again.

@acmeydan this is simple script using Coroutines. Remember to add this script and Rigidbody to light and check that all colliders are not triggers.

public class enablemeshrenderer : MonoBehaviour{
public float timeenabled;

void OnCollisionEnter(Collision col)
{
    if (col.gameObject.name == "Nameoftrainineditor")
    {
        StartCoroutine(Light());
    }
}
   IEnumerator Light()
{
     this.GetComponent<MeshRenderer>().enabled = true;
     yield return new WaitForSeconds(timeenabled);
     this.GetComponent<MeshRenderer>().enabled = false;
}

}