Another "ball rolling down the ramp" i've looked through the physics forum without finding the problem solved. 1. The problem statement, all variables and given/known data I want to compare theoretical and practical data, with a ball "rolling" down a ramp. the problem comes when i try to measure all the factors, so far the things i NEED to get in the equations: Rolling resistance Windforce / aoredynamics I also think there should be something about "boyle-mariottes law" basically get the theoretical as close to the practical as possible Data ball weight: 0.696kg ball radius: 3 cm ramp length: 207 cm ramp height: 4 cm 3. The attempt at a solution My idea was to compare acceleration by setting windforce to 0 (thats why the low height). i got around 0.18 newton in theory and 0.05 in practice(the force on the ball) . therefore im asking for some guidens, now what to do ? and how to do ? i hope your understand my problem, because im not the best at making others understand and ofcourse looking forward to some help. if you need some more data, please ask and ill try to get it as soon as possible (: Regards Jesper.