Accelerate rigidbody by a specific value

I want to add a constant acceleration of 2 m/s^2 to my GO, but can’t figure out how.

I already tried various Force modes, but don’t really understand how exactly the force is added even after reading the documentation.

thanks in advance

I’m not that much of a professional programmer but you can use this script as an exaple of adding a specific acceleration:

var Acceleration : float = 2;

function FixedUpdate () //everything physics related is best if added in fixed update because it doesn't depend on framerate so you will have the same physics even with 30 fps and 300.
{
       if (Input.GetKey ("w")) //you can put any key or button you want
      {
           rigidbody.AddForce (Vector3.forward * Acceleration);
      }
}

Please note that adding force to a rigidbody will make you go faster and faster so you might want to make a speed limit.

hi if I understand your problem (I’m pretty bad in English) but you would like to add a force of 2 every 2 seconds … Have you tried this:
//I don’t know what is your language to code but it’s an example in JS

var seconde : float;
var timeToPutForce : float;
var myForce : float;

function Update (){
    seconde+=1*Time.deltaTime;
    if ( seconde>=2){
       seconde = 0;
       myforce+=2;
    }
    rigidbody.AddForce(Vector3(0,0,myForce), ForceMode.Impulse);
}