speed(v),velo=s/t or P/t delta price/time (, mph, price bar)
accel(a)= (v0-v1)/t or delta speed/time; (t^2, second deriv. ROC, Momentum - many indis in diff forms exploit and present this effect
also:
codebas:
????????? Acceleration&Speed.... - MQL4 Code Base
forum:
????????? Acceleration&Speed - MQL4 ?????
p.s. sorry, if we already have this or similar, i'll take it off