Average Acceleration

Average acceleration, abbreviated as \( \bar {a} \), is the change of velocity over an elapsed amount of time.  Whereas, instantaneous accleration is the change of velocity at a specific point in time.  As an example, if a vehicle is initially traveling at 100 feet per second and slows down to 50 feet per second over 60 seconds, the average acceleration over 60 seconds is - 8.3 ft per second.  The equation and calulation for average acceleration is shown below. 

 

Average acceleration formulas
\(\large{ \bar {a} = \frac{ \Delta v }{ \Delta t }  }\)  \(\large{ \bar {a} = \frac{ v_f \;-\; v_i }{ t_f \;-\; t_i }   }\)
Symbol	English	Metric
\(\large{ \bar {a} }\) = average acceleration	\(\large{\frac{ft}{sec^2}}\)	\(\large{\frac{m}{s^2}}\)
\(\large{ \Delta t }\) = time change	\(\large{sec}\)	\(\large{s}\)
\(\large{ t_f }\) = final time	\(\large{sec}\)	\(\large{s}\)
\(\large{ t_i }\) = initial time	\(\large{sec}\)	\(\large{s}\)
\(\large{ \Delta v }\) = velocity change	\(\large{\frac{ft}{sec}}\)	\(\large{\frac{m}{s}}\)
\(\large{ v_f }\) = final velocity	\(\large{\frac{ft}{sec}}\)	\(\large{\frac{m}{s}}\)
\(\large{ v_i }\) = initial velocity	\(\large{\frac{ft}{sec}}\)	\(\large{\frac{m}{s}}\)