I suspect F was fixed and the curves were showing how m/a varied in that case, in a similar fashion to these plots for momentum: https://frdmtoplay.com/on-a-res

I suspect F was fixed and the curves were showing how m/a varied in that case, in a similar fashion to these plots for momentum: https://frdmtoplay.com/on-a-researchers-momentum/ https://frdmtoplay.com/on-a-researchers-momentum/