Question

6. 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 point)
95.1s and 108.7s
10.2s and 101.9s
108.7s and 10.2s
95.1s and 10.2s

Answer 1

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


now just stick the value d=0.1 into (1) and (2) above to get your answer (remember to multiply the answers you get by 3600 to convert hours to seconds).

Answer 2

I'm screwed for the test!

Answer 3

what do you mean

Answer 4

this one of the questions I have to do on the test. The teacher gives us a couple of questions from the test to show us what we need to know.