sirryan1 3 years ago Starting from 1.5 miles away, a car drives toward a speed checkpoint and then passes it. The car travels at a constant rate of 53 miles per hour. The distance of the car from the checkpoint is given by d = |1.5 – 53t|. At what times is the car 0.1 miles from the checkpoint? Calculate your answer in seconds.

1. geoffb

Make it into an equation. How many solutions do you expect to have?

2. sirryan1

95.1s and 108.7s 10.2s and 101.9s 108.7s and 10.2s 95.1s and 10.2s

3. geoffb

Okay, it's multiple choice, so I guess the answers gave away my second question. I was asking *you*. Have you written out an equation?

4. sirryan1

no

5. sirryan1

@kelly226 can you help?

6. kelly226

d=|1.5−53t| where d is in miles and t is in hours. first divide both sides by 53 to get: d53=|1.553−t| this can be split into two portions: (1) for t <= 1.5/53 hours we can write: d53=1.553−t t=1.5−d53 (2) for t > 1.5/53 hours we can write: d53=−(1.553−t)=t−1.553 t=1.5+d53

7. sirryan1

i dont get it

8. geoffb

Of course you don't. You haven't written out an equation yourself. It makes perfect sense that you don't understand it.