Question

2 A marathon race is 42 195 m in length. The world record in 2016 was

2 hours, 2 minutes and 57 seconds held by Dennis Kimetto of Kenya.
a How many seconds in total did Kimetto take to complete the race?
b Calculate his average speed in m/s for the race, giving your answer to
2 decimal places.
c What average speed would the runner need to maintain to complete
the marathon in under two hours?

Answer 1

A. 7377 s

B. 5.72 m/s

C. 5.86 m/s

Explanation:

A. Determination of the time in second.

Time (t) = 2 hours, 2 minutes and 57 seconds

We'll begin by converting 2 hours to seconds. This can be obtained as follow:

1 hour = 3600 s

Therefore,

2 hour = 2 hours × 3600 s / 1 hour

2 hours = 7200 s

Next, we shall convert 2 mins to seconds. This can be obtained as follow:

1 min = 60 s

Therefore,

2 mins = 2 mins × 60 s / 1 min

2 mins = 120 s

Finally, we shall determine the total time in second. This can be obtained as follow:

2 hours, 2 minutes and 57 seconds = 7200 s + 120 s + 57 s

= 7377 s

Therefore, the total time in second is 7377 s

B. Determination of the average speed.

Total distance = 42195 m

Total time = 7377 s

Average speed =?

Average speed = Total distance / total time

Average speed = 42195 / 7377

Average speed = 5.72 m/s

Therefore, the average speed is 5.72 m/s

C. Determination of the average speed.

We'll begin by converting 2 hours to seconds. This can be obtained as follow:

1 hour = 3600 s

Therefore,

2 hour = 2 hours × 3600 s / 1 hour

2 hours = 7200 s

Finally, we shall determine the average speed. This can be obtained as follow:

Total distance = 42195 m

Total time = 7200 s

Average speed =?

Average speed = Total distance / total time

Average speed = 42195 / 7200

Average speed = 5.86 m/s

Therefore, the average speed is 5.86 m/s.