How can i set AddRelativeForce relative to how fast/slow im moving my mouse?

Hi, I want to open a door by dragging with my code. The door retains a constant velocity though no matter how fast or slow i drag my mouse. Is there someway to set the force relative to my mouse speed? Thanks!

 function Update()
 {
     onMouseDrag();
 }
 
 function onMouseDrag()
 {
     if(Input.GetMouseButton(0))
     {
         rigidbody.drag = 0;
         if(Input.GetAxis("Mouse X")>0)
         {
             rigidbody.AddRelativeForce (Vector3.forward * 1);
         }
         
         if(Input.GetAxis("Mouse X")<0)
         {
             rigidbody.AddRelativeForce (Vector3.back * 1);
         }
     }
     else
     {
         rigidbody.drag = 3;
     }
 }