Hi I am doing an assignment where I roll a tin can filled with car oil. This will affect its rolling because it distorts its centre of mass, resulting in an awkward rolling motion. I have already done the experiment, the first revolution is the slowest one by a lot because it slows down a lot when it's halfway through the revolution. Afterwards it speeds up by a lot. I assume this happens because when the tin can is released, all of the oil is at the bottom (it's not full) and as it reaches half a revolution the oil is on top. Moving it upwards slows down the tin can and then it accelerates because the oil is moving forwards. In any case, I would find any link or formula regarding centres of mass to be very useful. Thanks for the help.