Answer:
9.83 km/h
Explanation:
Given: in a 4 kilometer race, a runner completes the first kilometer in 5.9 minutes, the second kilometer in 6.2 minutes, the third kilometer in 6.3 minutes, and the final kilometer in 6 minutes.
To Find: the average speed of the runner for the race.
Solution:
In a 4 kilometer race,
time required to travel first kilometer = [tex]5.9[/tex] [tex]\text{minutes}[/tex]
time required to travel seoond kilometer = [tex]6.2[/tex] [tex]\text{minutes}[/tex]
time required to travel third kilometer = [tex]6.3[/tex] [tex]\text{minutes}[/tex]
time required to travel final kilometer = [tex]6[/tex] [tex]\text{minutes}[/tex]
we know that,
[tex]\text{Average speed}=\frac{\text{Total distance traveled}}{\text{Total time taken}}[/tex]
Total distance traveled = [tex]4[/tex] [tex]\text{kilometer}[/tex]
Total time taken = [tex](5.9+6.2+6.3+6)[/tex]
= [tex]24.4[/tex] [tex]\text{minutes}[/tex]
= [tex]\frac{24.4}{60}[/tex] [tex]\text{hours}[/tex]
putting values,
[tex]\text{Average speed}=\frac{4}{\frac{24.4}{60}}[/tex]
[tex]\text{Average speed}=\frac{4\times60}{24.4}[/tex]
=[tex]9.83[/tex] [tex]\text{km}/ \text{h}[/tex]
the average speed of the runner for the race is approximately [tex]9.83[/tex] [tex]\text{km}/ \text{h}[/tex]
