Need Help With Error in Shooting Script C#

Questions & Answers
1

Keep coming back withing an error in my script when I try to shoot. the problem is coming from line 12 , but I’m not sure what is happening. Here’s my script:

using UnityEngine;
using System.Collections;

public class Shoot : MonoBehaviour {

public KeyCode shoot;

// Use this for initialization
void Update () {
	
	if (Input.GetKey (shoot)) {
		Vector3 sp = Camera.main.WorldToScreenPoint(transform.position);
		Vector3 dir = (Input.mousePosition - sp).normalized;
		rigidbody2D.AddForce (dir * 500);
		
	}
}
void OnTriggerEnter2D(Collider2D other) {
	if (other.gameObject.name == "enemy") {
		Destroy (other.gameObject);
	}
	if (other.gameObject.name == "player") {
		Destroy (this.gameObject);
	}
}

}

2

I think you can’t access rigidbody2D directly.

Instead of rigidbody2D.AddForce (dir * 500);
Try :

GetComponent < RigidBody2D >().AddForce (dir * 500);