Question

Question #6a426

Answer 1

Answer: `Deltat=3.9` `sec`

Explanation:

First, we can write out the given information:
`v_i=18.1` `m"/"s`
`a=-2.7` `m"/"s^2`
`v_f=7.6` `m"/"s`

Since we are looking for `Deltat`, the change in time, we can use the equation:
`v_f=v_i+aDeltat`

Solving for `Deltat`:
`aDeltat=v_f-v_i`

`Deltat=(v_f-v_i)/a`

Now we can substitute in our given values to find `Deltat`:
`Deltat=(7.6-18.1)/(-2.7)=3.89` or `3.9` `sec` to 2 significant figures.