a \bullet\ train set a new world record for train speed at 553 kilometers per hour during a manned test run…

a \bullet\ train set a new world record for train speed at 553 kilometers per hour during a manned test run on a test line. the test line is 43.1 kilometers long. how many minutes would a test run on the test line last at this record - setting speed? a test run would last (round to two decimal places as needed.)
Answer
Explanation:
Step1: Recall the time - distance - speed formula
We know that $t=\frac{d}{v}$, where $t$ is time, $d$ is distance, and $v$ is speed.
Step2: Convert the speed to km/min
The speed $v = 553$ km/h. To convert it to km/min, we use the conversion factor: $1$ hour=$60$ minutes. So $v=\frac{553}{60}$ km/min.
Step3: Calculate the time
The distance $d = 43.1$ km. Using the formula $t=\frac{d}{v}$, we substitute $d = 43.1$ km and $v=\frac{553}{60}$ km/min. So $t=\frac{43.1}{\frac{553}{60}}=43.1\times\frac{60}{553}$. $43.1\times\frac{60}{553}=\frac{2586}{553}\approx4.68$.
Answer:
$4.68$