contestada

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?​

Respuesta :

calculista

we know that

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

[tex]d=\left|300-48t\right|[/tex]

Find the times t for [tex]d=60\ feet[/tex]

substitute the value of d in the equation

[tex]60=\left|300-48t\right|[/tex]

Solve for t

There are two solutions

First Solution

[tex]60=+(300-48t)[/tex]

[tex]60=300-48t[/tex]

[tex]48t=300-60[/tex]

[tex]48t=240[/tex]

[tex]t=240/48[/tex]

[tex]t=5\ sec[/tex]

Second Solution

[tex]60=-(300-48t)[/tex]

[tex]60=-300+48t[/tex]

[tex]48t=300+60[/tex]

[tex]48t=360[/tex]

[tex]t=360/48[/tex]

[tex]t=7.5\ sec[/tex]

therefore

the answer is

At the time [tex]t=5\ sec[/tex] and at the time [tex]t=7.5\ sec[/tex]

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