# Question #841cf

Change in velocity is called acceleration. To calculate the acceleration of an object over a given time interval you can measure the initial velocity (${v}_{i}$) at some time and then the final velocity (${v}_{f}$) some time later. In the equation below the initial time is noted as ${t}_{i}$ and the final time as ${t}_{f}$.
$a = \frac{{v}_{f} - {v}_{i}}{{t}_{f} - {t}_{i}}$
$a = \frac{32 - 0}{4 - 0} = 8 \frac{m}{{s}^{2}}$