How to control the speed of AddForce (ForceMode.Impulse)?????

When I adjust the ‘speed’ of the AddForce, it actually adjusts the distance of how far my object dashes forward. If I increase the ‘speed’ (now called dashDistance) it just makes the object dash further. But the speed of the dash stays the same (it dashes almost in a blink), which is not realistic. How can I make my object dash in a ‘slower’ speed?

private float dashDistance = 75;

        if (Input.GetKeyDown(KeyCode.X))
            Vector3 camDirection = Camera.main.transform.forward; camDirection.y = 0.0f;
            rb.AddForce(camDirection * dashDistance, ForceMode.Impulse);

            transform.rotation = Quaternion.LookRotation(camDirection); 

changing the mass of the object may slow it down. Had a similar issue,@ngerbens
had this issue as well. I changed the mass of the object and the heavier it was the slower it went.