AddForce Problem

I am making a game and I have some problems with addforce…
I need to add AddForce because ball does not have gravity, anyway the point of game is keep ball inside of box as you can see on image:

but I want to add more speed when player score is > 10 and so on, at first my AddForce was on Start function and everything was working fine except ball always had same speed and it is logical because it was on Start function so I moved it to Update function and now I have problem, ball speeds up every frame and I don’t wont that I want ball to go X speed when score is < 10 and so on…
here is some image of script

You’re adding force every cycle so it’s going to get out of control quickly. Add a boolean or some other way to register that the force has been added for each score gate you want.

I try to add bool but if i put addforce it get out of control again, but i solved the problem Adding faster time.timescale

On Line 44 your comparison should be > not <.
I’d like to see how score gets increased because i think that would be the right place to add your force so it only happens once (as score increases to above some Limit).
However the solution whogas mentioned would also work but might be more code to write.
You would have to create a bool for each Force increase all of them initialized false and set to true when force is increased and in your if Statement you have to check the respective bool to equals false. like that:

bool addForce1=false;

void Update(){
 if(score>10 && !addForce1){
  ballRB.AddForce(movement * 0.7f);
  addForce1=true;
 }
}