Calculating "Additional" Braking Torque Due To Momentum Hi, First off this is not a homework problem :-) I'm trying to understand how one could calculate the "additional" torque that vehicle brakes have to apply due to it's momentum? I have been told that when you consider the vehicle a "closed system" then you don't have to worry about momentum. However, my case would be more like if I could attach an external torque sensor to the brakes and see the values due to different masses at a given velocity. The same set of brakes have to work harder to stop a fully loaded semi-truck versus an empty one in the same time/distance, right? I know that momentum is p=mv and t=fd and I will have to look at an instance/moment of time as the velocity of the vehicle will change as the brakes are applied which is fine. I would like to know how to make this calculation to determine the torque/forces applied to say the front wheel where it touches the ground. So for example what would be the instantaneous momentum torque for a 1000kg vehicle travelling at 100km/hr at the front wheel the moment the brakes are applied? I hope this makes sense. Thanks for your help!