Change a specific Gameobjects rigidbody gravity to horizontal (left)

Hey guys im new with Unity. Right now im trying to make a 2D game. I have a Gameobject (a ball) with a Rigidbody component but i want only this gameobject to be pulled to the left, just like when the rigidbody standard gravity pulls it down. I know how to do it in the menu under edit - project setting - ..., but that will set alle rigidbody to have the same gravity direction which is a problem in my case. Hope u guys can help thx u.