Question

Starting from 300 feet away, a car drives toward you. It then passes by you at a speed of 48 feet per second. The distance dd (in feet) of the car from you after tt seconds is given by the equation ​d=|300−48t|​d=|300−48t|. At what times is the car 60 feet from you?​

Answer 1

we know that

The distance d (in feet) of the car from you after t seconds is given by the equation

`d=\left|300-48t\right|`

Find the times t for
`d=60\ feet`

substitute the value of d in the equation

`60=\left|300-48t\right|`

Solve for t

There are two solutions

First Solution

`60=+(300-48t)`

`60=300-48t`

`48t=300-60`

`48t=240`

`t=240/48`

`t=5\ sec`

Second Solution

`60=-(300-48t)`

`60=-300+48t`

`48t=300+60`

`48t=360`

`t=360/48`

`t=7.5\ sec`

therefore

the answer is

At the time
`t=5\ sec` and at the time
`t=7.5\ sec`