How to add baloon physics in unity3d.currently i am done with detecting sphere object

Unity Engine
,
1

where i swipe or flick sphere…but after flicking sphere while coming its down i want it to slow its speed…(like baloon) i want to hv baloon physics…plz help guys…

2

A real balloon has low mass and high drag. Adjust your parameters to reflect this.

3

thnx alot…

4

currently in my swipe or flick code does not detect the sphere or baloon object…my gameobjects flicks even if i swipe or flicks to screen …so now i want to detect sphere or baloon object and if i swipe on it then only it should travel upward…here is code… plz help guys…

using UnityEngine;
using System.Collections;

public class TouchMonitor : MonoBehaviour {
	//var theprefab:GameObject;
	
    public Rigidbody ball;

    private Vector3 touchStart; 
    private Vector3 touchEnd;
    private GameObject lineRenderer; 
	
	
	
	

    void Update () {
        if (Input.touchCount > 0)
        {
            Touch t = Input.touches[0];
            if (t.phase == TouchPhase.Began)
            {
                touchStart = t.position;
            }

            if (t.phase == TouchPhase.Ended || t.phase == TouchPhase.Canceled)
            {
                touchEnd = t.position;
                DoInput();
            }
        }

        if (Input.GetButtonDown("Fire1"))
        {
            touchStart = Input.mousePosition;
        }

        if (Input.GetButtonUp("Fire1"))
        {
            touchEnd = Input.mousePosition;
            DoInput();
        }
    }
	//Start
	
	
	//end
    void DoInput()
    {
		
        Vector3 p1 = new Vector3();
        Vector3 p2 = new Vector3();
        touchStart.z = Camera.main.nearClipPlane+.1f; //push it a little passed the clip plane for camera, just to make sure its visible on screen
        touchEnd.z = Camera.main.nearClipPlane+.1f;
        p1 = Camera.main.ScreenToWorldPoint(touchStart);
        p2 = Camera.main.ScreenToWorldPoint(touchEnd);

        CreateLine(p1,p2);

        Vector3 v = p2-p1;
        ball.AddForce(v*10, ForceMode.Impulse);
    }

    //creates an  purple line from pos1 to pos2 in worldspace
    void CreateLine(Vector3 p1, Vector3 p2)
    {
        Destroy(lineRenderer);
        lineRenderer = new GameObject();
        lineRenderer.name = "LineRenderer";
        LineRenderer lr = (LineRenderer)lineRenderer.AddComponent(typeof(LineRenderer));
        lr.SetVertexCount(2);
        lr.SetWidth(0.001f, 0.001f);
        lr.SetPosition(0, p1);
        lr.SetPosition(1, p2);
    }
}