One_Button_Game/OneButtonGame/Assets/Scripts/centerOfMass.cs

using UnityEngine;
using System.Collections;

public class centerOfMass : MonoBehaviour {

    public GameObject marker;
    public Rigidbody2D rigid;

	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {
        Vector3 temp = rigid.worldCenterOfMass;
        temp.z-= 0.2f;
        marker.transform.position = temp;
	
	}
}