Question

how long does it take a car to accelerate from 3.4m/s to 20.9m/s if the average acceleration is 6.0m/s (squared).

Answer 1

Average acceleration is the ratio of the change in velocity to the time it takes for that change to occur:

`a_{\mathrm{av}}=(\Delta v)/(\Delta t)`

We want to find
`\Delta t`:

`6.0\,(\mathrm m)/(\mathrm s^2)=(20.9\,(\mathrm m)/(\mathrm s)-3.4\,(\mathrm m)/(\mathrm s))/(\Delta t)`

`\implies\Delta t=2.9\,\mathrm s`