PSim.cs

using UnityEngine;

public class PSim : MonoBehaviour {

    [SerializeField][Range(1, 5)] float maxTime = 0.1f;

    private void Awake()
    {
        Physics.autoSimulation = false;
    }

    private void Start()
    {
        float time = 0;
        while(time < maxTime)
        {
            Physics.Simulate(Time.fixedDeltaTime);
            time += Time.fixedDeltaTime;
        }
    }

    private void OnDestroy()
    {
        Physics.autoSimulation = true;
    }
}