Question

A car traveling at 23m/s starts to decelerate steadily. It comes to a complete stop in 7 seconds. What is the acceleration?

Answer 1

The car has an initial velocity
`v_0` of 23 m/s and a final velocity
`v` of 0 m/s. Recall that for constant acceleration,

`v=v_0+at`

The car stops in 7 s, so the acceleration is

`0\,(\mathrm m)/(\mathrm s)=23\,(\mathrm m)/(\mathrm s)+a(7\,\mathrm s)`

`\implies a\approx-3.29\,(\mathrm m)/(\mathrm s^2)`