Formulae

for Physics Kinematics

Given:
• d = distance
• t = time
• v = speed
• a = acceleration
• Δ = Difference or change from a previous value to a subsequent value
Note:   Δ (pronounced Delta) is the 4th letter of the Greek alphabet, much as D (as in Difference) is the 4th letter in the English alphabet.   It might be helpful to recall that a river delta, named for a shape similar to the Δ, is a transitory land formation where the river often changes it path though the low land.

Kinematics Formulae

Note:   Any difference can be found from the value of a latter item by subtracting the value which preceded it:

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  