Why does the character move jerkily?

Question

Unity

public GameObject player;
    public GameObject createObj;
    public Rigidbody2D rigidbody2D;
    public float speed = 10f;

    private void Start() 
    {
        rigidbody2D = player.GetComponent<Rigidbody2D>();
    }

    private void Update() 
    {
        rigidbody2D.velocity = new Vector2(1 * speed, rigidbody2D.velocity.y);
    }
}

For some reason it jerks

Answer 1

Something tells me that you forgot about Time.deltaTime. Just write:

private void Update() 
    {
        rigidbody2D.velocity = new Vector2(1 * speed * Time.deltaTime, rigidbody2D.velocity.y);
    }