I am currently working on bullet impact on the target. As you all know, after the interaction with the target of the bullet, the speed of it begins to fall. In my work, the bullet had 820 m/s before impact. However, I don't know the exact function of the time. I just wrote the value and selected constant speed. As far as I understood, that bullet never loses its speed. But I want to have real conditions. Is there any way to make the speed of the bullet related with target strength. Or did I make the true thing? Any help is appreciated. Thanks in advance.