cannon.GetComponent<Transform>().rotation = cannon.GetComponent<Transform>().rotation.x >= 0 && returnGroundAngle() <= 85 ?
                new Quaternion(cannon.GetComponent<Transform>().rotation.x - 0.02f,
                cannon.GetComponent<Transform>().rotation.y, cannon.GetComponent<Transform>().rotation.z, cannon.GetComponent<Transform>().rotation.w)
                : cannon.GetComponent<Transform>().rotation;