Rotating a gameobject to a specific point [duplicate]

Answer 1

You should do this with coroutine. Call the coroutine function and pass in the GameOjbect to rotate and the angle to rotate to when OnCollisionEnter is called. You can read how this function work here.

Te example below will rotate the GameObject -85 degree in z-axis within 3 seconds. You can change that to whatever suits you.

public class fallBridge : MonoBehaviour
{
    private Rigidbody ball;
    public GameObject bridgePivot;
    bool rotating = false;

    void OnCollisionEnter(Collision other)
    {
        ball = GameObject.FindWithTag("Player").GetComponent();
        if (other.gameObject.CompareTag("Player") && ball.transform.localScale == new Vector3(2.0f, 2.0f, 2.0f))
        {
            Debug.Log("ENTER");
            Vector3 rotationAngle = new Vector3(0, 0, -85);
            StartCoroutine(RotateObject(bridgePivot, rotationAngle, 3f));
        }
    }

IEnumerator RotateObject(GameObject gameObjectToMove, Vector3 eulerAngles, float duration)
{
    if (rotating)
    {
        yield break;
    }
    rotating = true;

    Vector3 newRot = gameObjectToMove.transform.eulerAngles + eulerAngles;

    Vector3 currentRot = gameObjectToMove.transform.eulerAngles;

    float counter = 0;
    while (counter < duration)
    {
        counter += Time.deltaTime;
        gameObjectToMove.transform.eulerAngles = Vector3.Lerp(currentRot, newRot, counter / duration);
        yield return null;
    }
    rotating = false;
}