Question

if the same ball rolls down from three different length trackways with a 20degrees elevation, its acceleration on the short-length trackway is 1.08m/s^2;its acceleration on the medium-length trackway is 1.79m/s^2;and its acceleration on the long-length trackway is 1.52m/s^2.

how do the values of aS,aM, and aL compare and account for the results and any diffrences.

what do you mean by aS, aM, and aL ?

aS=the acceleration of the ball on short-length trackway
aM=the acceleration of the ball on medium-length trackway
aL=the acceleration of the ball on long-length trackway

Well, assume the ball is rolling. Friction will have a greater effect on the long track, as it operates for a longer distance. That accounts for the difference between the medium and long.

I cant explain the short length, it should be a higher value, in my thinking.