Add force to enemy who got shot at

So I’ve got an AI and a Ragdoll, If the AI dies the AI is removed and a ragdoll spawns in it’s place. The ragdoll just falls flat down on the floor and thats not want I want. I want to be able to kill the enemy and force is applied to the ragdoll from the direction the player shot from - Just like half life 2.

I read some threads about this subject and I saw someone saying that you should add a rigidbody attached to the ragdoll and apply force to that rigidbody.
So I tried doing that - script below

	public float power = 10.0f;
	// Use this for initialization
	void Start () 
		SawedShotgun s = GetComponent<SawedShotgun> ();
		transform.GetComponentInChildren<Rigidbody> ().AddForce (s.shotgun.transform.forward * power);

I’m getting an error saying Object reference not set to an instance of an object from

transform.GetComponent ().AddForce (s.shotgun.transform.forward * power);

If anyone could help me with this script and why it aint working it would be so great.

fuck yeah, it works!! Thanks dude