Hello everyone, im really new to unity and i was trying to get a sphere to jump then i got an error "An object reference is required to access non-static member". I want to learn how to fix this

Here is my code...

using UnityEngine; using System.Collections;

public class jump : MonoBehaviour {

 public float sphereJump = 10;
 Rigidbody spherebody;

 
 void Awake () {
     spherebody = GetComponent<Rigidbody>();
 }
 
 
 void FixedUpdate () {
     if (Input.GetButtonDown ("Jump"))
         Rigidbody.AddForce (0 ,sphereJump ,0);

 
 }

}

i really need help thanks