Respuesta :
Answer:
4.5m /s
Explanation:
42.0/2.57 =16.34km/h
16.34/60=0.27km or 270m/m
270/60=4.5m/s
Average speed of a body is the ratio of total distance covered by it to the total times taken. The average speed of the runner is 3.96 m/s.
Given information
The length of the marathon is 42 km (approx.).
The time taken by the runner to ran the marathon is 2 hours and 57 minutes.
What is average speed?
Average speed of a body is the ratio of total distance covered by it to the total times taken.
Average speed of a body can be given as,
[tex]\overline s=\dfrac{\Delta x}{\Delta t}[/tex]
The total distance covered by the runner is 42 km. As there is 1000 m in 1 km. Thus the distance covered by the runner in meter is,
[tex]\Delta t=42\times1000[/tex]
The total time taken by him is 2 hours 57 minutes. Convert this time into minutes,
[tex]\Delta t=60\times2+57\\\Delta t=177[/tex]
Convert the time in seconds,
[tex]\Delta t=177\times60[/tex]
Thus the average speed of the runner can be given as,
[tex]\overline s=\dfrac{42\times1000}{177\times60}\\\overline s=3.96[/tex]
Hence the average speed of the runner is 3.96 m/s.
Learn more about the average speed here;
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