Check out example codes for "Rigidbody.addforce". It will help you in understanding the concepts better.

Code Example 1

using UnityEngine;public class ExampleClass : MonoBehaviour
{
    public float thrust = 1.0f;
    public Rigidbody rb;    void Start()
    {
        rb = GetComponent<Rigidbody>();
        rb.AddForce(0, 0, thrust, ForceMode.Impulse);
    }
}

Code Example 2

rb = GetComponent<Rigidbody>();
rb.AddForce(new Vector3(1.5f,1.5f,1.5f));

Learn ReactJs, React Native from akashmittal.com