wazzup

I do not know if this is the correct section? sorry if not and could you please tell me what branch i need. I have many "pellets" which are cone shaped. the rear is always 6mm in dia ,the front is 4.5mm. This 4.5mm size varies slightly in manufacture. it is very time consuming measuring with a digital caliper. i have seen a video on YT of a guy using a great method. the video is not great quality with no sound. what he uses is a raised piece of wood to form a ramp. he puts a pellet at the top corner and lets go. the pellet rolls in a arc. the pellets roll in different arcs depending on the size. he made little pots along the board edge to catch the pellet sizes. What i do not understand is....... is there a calculation of the arc using the 2 dia sizes of the pellet does the height of the slope effect the way any pellet rolls hope that make sense,thank you