RigidBody2D速度，运动问题

Question

我试图以RigidBody2D速度向上移动对象，但是代码不起作用。

    SantaRb.velocity = new Vector3(0f, rocketFlyBoost, 0f);

    Vector3 mPosition = Camera.main.ScreenToWorldPoint(new Vector2(Input.mousePosition.x, transform.position.y));
    transform.position = Vector2.Lerp(transform.position, mPosition, moveSpeed);
    Vector3 difference = Camera.main.ScreenToWorldPoint(Input.mousePosition) - transform.position;
    difference.Normalize();
    float rotation_z = Mathf.Atan2(difference.y, difference.x) * Mathf.Rad2Deg;
    transform.rotation = Quaternion.Euler(0f, 0f, rotation_z -90f);

如果我注释掉第一行之外的所有行，则该对象移动正常。我错了，非常感谢！