Make GameObject fly

I have this code:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class CubeTest : MonoBehaviour {
6.     public string Hello;
7.     float life = 100;
8.     public float speed = 1.5f; //vitesse cube
9.     public Rigidbody cube;
10.  
11.     // Use this for initialization
12.     void Start () {
13.         Debug.Log (Hello + "You have" + life + "%");
14.         cube = GetComponent<Rigidbody> ();
15.             cube.mass = 2;
16.             cube.drag = 0;
17.             cube.isKinematic = false;
18.         cube.AddForce (Vector3.up * 10);
19.     }
20.  
21.    
22.     // Update is called once per frame
23.     void Update () {
24.         transform.position += new Vector3 (0, 2, 0) *Time.deltaTime;
25.     }
26. }
27.  

With this, I just want make my GameObject(cube) fly in the air and it make this:
https://gyazo.com/a4308faec561c6f8fa4818dade776ae4
I found one solution is to take off the

Code (CSharp):

1. *Time.delta.time

but it doing this:
https://gyazo.com/2074ee9ccd8cf9604c2f20e70c6ffb5c

 

Post this question in the Scripting forum. This is not Documentation-related.

 

oK, but can you ansewer me, if you know ?