[Mentor's Note: Thread moved to Introductory Homework Forum] What's up. I have this question in my physics book regarding what forces do. Can I please get help with this question. A utility vehicle has a maximum acceleration of 6.0 m/s when it carries only the driver and has a total mass of 5000 kg. What is it's maximum acceleration after picking up six passengers and their luggage, adding an additional 800 kg mass? Basically, my maths is a bit rusty, so I thought I would write it like 800/5000 X 6.0, which gave me 0.96, obviously wrong. The answer is 5.2 m/s, which just seemed odd to me. Keep in my mind, they haven't introduced Newtons second law in the book yet. All I know is that acceleration is inversely proprortional to mass. Also, can anyone explain why we put squared inddicie next to the seconds in m/s. I suck at maths and Physics so badly, so please forgive me if this is an extremely dumb thread. Yes, I am an undergraduate who has never done much physics before.