Answer: 400 seconds
Step-by-step explanation:
For this exercise it is necessary to remember the following formula:
[tex]V=\frac{d}{t}[/tex]
Where "V" is speed, "d" is the distance and "t" is the time.
If you solve for the time, you get:
[tex]t=\frac{d}{V}[/tex]
In this case you can identify that that the average speed and the distance are:
[tex]V=5.00\ \frac{m}{s} \\\\d=2.00\ km[/tex]
You need to make the conversion from kilometers to meters. Since:
[tex]1\ km=1,000\ m[/tex]
You get:
[tex](2.00\ km)(\frac{1,000\ m}{1\ km})=2,000\ m[/tex]
Therefore, substituting values into [tex]t=\frac{d}{V}[/tex] and evaluating, you get the time is:
[tex]t=\frac{2,000\ m}{5.00\ \frac{m}{s}}\\\\t=400\ s[/tex]