How to Handle multiple health of same instance?

So i have parent class named car and I created child class of that, and there is a variable named health, which is shown through a widget, when i create multiple instances of child class, they all share the same health, for eg when i hit a car (a), the another car (b) is also affected, what should i do?

I sir I have the same problem But with BLOCKs…
Since we both share similar goals lets help each other!