Can't use Rigidbody.Sleep() because I need to reference an object?

Questions & Answers
1

I’m trying to finish this bullet shell script so they can eject whenever I shoot, and I came across this error when using Rigidbody.Sleep:
“An object reference is required to access non-static member `UnityEngine.Rigidbody.Sleep()'”

All I know is the prefab I’m using is not static but

using UnityEngine;
using System.Collections;

public class Shell : MonoBehaviour {

	private float lifeTime = 5;

	private Material mat;
	private Color originalCol;
	private float fadePercent;
	private float fadeTime;
	private bool fading;

	void Start () {
		mat = GetComponent<Renderer>().material;
		originalCol = mat.color;
		fadeTime = Time.time + lifeTime;
		StartCoroutine ("Fade");
	
	}

	IEnumerator Fade()
	{
		while (true) {
			yield return new WaitForSeconds(.2f);
			if (fading){
				fadePercent += Time.deltaTime;
				mat.color = Color.Lerp (originalCol,Color.clear,fadePercent);

				if (fadePercent >= 1){
					Destroy(gameObject);
				}
			}
			if (Time.time > fadeTime){
				fading = true;
			}
		}
	}

	 void OnTriggerEnter(Collider c){
		if (c.tag == "Ground") {
			Rigidbody.Sleep();  // <-- This is my problem

		}
	}
}
2

Rigidbody is a class. You want the instance of that class attached to this Gameobject.

GetComponent<Rigidbody>().Sleep();