public GameObject bullet;
void Start () {
InvokeRepeating("F1", 1.0f, 3.0f);
}
void F1 () {
GameObject go = Instantiate(bullet, transform.position, Quaternion.Euler(0, 0, 0)) as GameObject;
go.GetComponent<Rigidbody2D>().AddForce(new Vector2(1, 1) * 125);
Destroy(go, 3.0f);
}