How to make realistic collision?

Hey dear experts,

I have an issue with my Scene. Basically what I want is, when the Knife and the white Barrier collide, the Knife should spin around and fall. However, currently my Knife just stop moving after the collision (because Gravityscale is 0).

I provide an image of the scene:

Thanks in advance! :slight_smile:

Just set the gravity scale to 1 when the knife collides with the white barrier:

using UnityEngine;

public class Knife : MonoBehaviour {

    Rigidbody2D rigid;

	// Use this for initialization
	void Start () {
        rigid = gameObject.GetComponent<Rigidbody2D>();

    private void OnCollisionEnter2D(Collision2D collision)
        if( == "WhiteBarrier")
        rigid.gravityScale = 1;

Also make sure there there is a Box Collider 2D attached to both the knife and the white barrier.