Carrara has a phsyics option. You set your object's animation setting to 'physics' and then add a force aimed downwards. Place a plane down, (NOT an infinite plane! They don't work properly for some reason.) Place your object somewhere up from the plane and run your animation. The 1st time through will take longer to play then subsequent playings since the physics engine has to do the math as to how your object should react with it's universe. The next time will be played without the extra math, unles you make a change. Then it will figure the physics out again. I've played with it some and found many cool reactions of objects. You can assign a couple of settings to your object on the effects panel of the properties tray. Hope this helps!