Jump is not working in 2D.

Hii..

I am New to Unity I am Creating sample app But right and left is working but jump is not working.

I am Getting Error

There is no 'Rigidbody' attached to the "ball_body" game object, but a script is trying to access it. You probably need to add a Rigidbody to the game object "ball_body". Or your script needs to check if the component is attached before using it.

How to solve this error.

Plz help me

Thank you.

 using UnityEngine;
 using System.Collections;

 public class TankController : MonoBehaviour
 {

  [HideInInspector]
 public bool jump = false;

 public float moveForce = 365f;
 public float maxSpeed = 5f;
 public float jumpForce = 1000f;

 private Transform groundDetector;
 public bool grounded = false;

 void Awake()
 {
     // Setting up references.
     groundDetector = transform.Find("GroundDetector");
 }

 void Update()
 {
     // The player is grounded if a linecast to the groundcheck position hits anything on the ground layer.
     grounded = Physics2D.Linecast(transform.position, groundDetector.position, 1 << LayerMask.NameToLayer("terrain"));

     // If the jump button is pressed and the player is grounded then the player should jump.
     if (Input.GetButtonDown("Jump") || Input.GetKey("w") && grounded)
         jump = true;
 }

 void FixedUpdate()
 {
     // Cache the horizontal input.
     float h = Input.GetAxis("Horizontal");

     if (h * rigidbody2D.velocity.x < maxSpeed)
         rigidbody2D.AddForce(Vector2.right * h * moveForce);
     if (Mathf.Abs(rigidbody2D.velocity.x) > maxSpeed)
         rigidbody2D.velocity = new Vector2(Mathf.Sign(rigidbody2D.velocity.x) * maxSpeed, rigidbody2D.velocity.y);

     // If the player should jump...
     if (jump)
     {
         rigidbody2D.AddForce(new Vector2(0f, jumpForce));
         jump = false;
     }
 }
 }