Fires a projectile in 2D

Fire Projectile 2D C#

void Update () {
if (contact == true) {
	if (Input.GetButtonDown ("Fire1")) {
		Vector3 layer = new Vector3 (launchPoint.transform.position.x , launchPoint.transform.position.y , 10f);
		GameObject go = (GameObject)Instantiate (shot,layer, Quaternion.identity);
		go.GetComponent <Rigidbody2D> ().velocity = new Vector2 (velocity.x * (transform.position.x + 6), velocity.y);
		Instantiate (recoilParticle, launchPoint.transform.position, Quaternion.identity);
		SD.Play ();
		shake = true;
	}
     }
}