Differenceor
changefrom a previous value to a subsequent value
Δ t = t final – t initial
(the elapsed time or difference between two times, Δt, is the latter or final
time less the earlier or initial
time.)
Δ d = d final – d initial
Δ v = v final – v initial
Δ a = a final – a initial
v average ≡ Δd / Δt true by physics definition!
a average ≡ Δv / Δt true by physics definition!
Note: An average can always be determined by summing the items then dividing by the number of items. This is easy if there are a small number of items. But caution must be observed if there are an infinite number of items and only the extreme items are averaged:
v average = ( v final + v initial ) / 2
a average = ( a final + a initial ) / 2
