Question Animation can't fire a particlesystem""fire ball"

I use a charcter with the Animation"""attack"" gesture, and I make a method , and the method will be called in
Animation"""Event""

Every thing works fine. Animation played, and particle play()

public class EnermyController : MonoBehaviour
{
public ParticleSystem particleSystem;

void MagicAttack()-->when animation starts
{
particleSystem.Play();
}

void StopMagic()--->when animation stops
{
particleSystem.Stop();

}
}


When I want tihs ParticleSystem"""Fire Ball"" will move forward when be played.

I don't know how to make this work.

particleSystem.Play();
particleSystem.transform.Translate(Vector3.forward*5*Time.deltaTime);
// no compilled erro, but it doesn't move

or

particleSystem embeded with Rigidbody

particleSystem.Play();
-->GetComponent<Rigidbody>().velocity = Vector3.forward*5

The fired ball just be played(), but it doesn't move..

I just can't figure out what the difference between moving a gameobject and a particlesystem""Fire Ball"