when i add ke translational + ke roatational, i dont get potential which i should, although i was wondering if maybe it was due to slipping although i thought it would still be closer than i got does this sound right? ke trans(0.002520831)+ke rotational (0.001008332) = 0.003529163 and pe=0.014278472 as you can see not very near it! is this right or have i gone wrong? the exp was rolling a ball bearing down a 5 degree slope and these calcs were from the 1m release mark. the radius is 0.00765m thanks to get the angular speed i used linear V/R (radius) i got linear v by divinding distance by time.