How to change physics setScale

Hi everyone.

I hope I can explain myself well with what I need. It may be a challenge for all of you.

I have a physics code. I copy it from the “bullets” the one that comes from corona.

in there I have this

physics.setScale( 36)

If I change that for 100 goes really fast, to 12 it goes really slow, 45 is good. I can change that in my editor, and it works fine, But I was thinking…

Is there a way that I can have 3 buttons, so when people “onRelease” the button,

They are the ones that actually are changing the numbers, to 100 to 12 or to 45?

--------------AND----------

Also following the same idea, changing the

bricks[n]:applyForce( 1600, 0, bricks[n].x, bricks[n].y )

Instead of 1600 to 2000 or 2387 or any number people one. Maybe have an slider to change the number.

I know maybe it’s too much but let’s see if someone is willing to share that secret code.

----------Finally---------

in this function

local function start()     -- throw 3 bricks     timer.performWithDelay( 300, throwBrick, 10 ) end

The program throws 10 bricks or “bullets”

can you tell me a way so people can change that for 4, or 29 with a button or slider?

I hope you understand my question, and you know how to do that, and you wish to actually let me know

how to do that.

Thank you in advance

Victor