Question

what is a race car's acceleration if its velocity changes from 0 m/s to 40 m/s in 4 seconds.

Answer 1

Acceleration=velocity/time.

Answer 2

\[\begin{align*}\vec{a} &= \frac{\Delta \vec{v}}{\Delta t}\\ \\ &= \frac{\vec{v}_f - \vec{v}_i}{t} \\ \\ &= \frac{(40 - 0)~\text{m/s}}{4~\text{s}} \\ \\ & \text{etc}\end{align*}\]