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10 votes
10 votes
Ava is competing in a 200 m race. She runs at a constant speed of 5.6 m/s for the first 50 m, then 4.6 m/s for 20 seconds. The remainder of the race takes her 26 seconds to complete. What is Ava's average speed for the entire race to 1 dp?

User David Gillen
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2 Answers

12 votes
12 votes
3.6 meters per second is the correct answer! Above is right
User Stanley Ulili
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19 votes
19 votes

Answer: 3.6 meters per second

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Step-by-step explanation:

The first 50 meters of the race is ran at a constant speed of 5.6 m/s.

Let's compute the time taken for this portion

distance = rate*time

time = distance/rate

time = 50/(5.6)

time = 8.92857

It takes approximately 8.92857 seconds to run the first 50 meters (at a constant speed of 5.6 m/s).

Add on the other time values from the other sections (20 and 26) to get 8.92857+20+26 = 54.92857

The entire 200 m race takes about 54.92857 seconds.

So Ava's average speed over the entire race is about 200/(54.92857) = 3.641092 which rounds to 3.6 m/s when rounding to one decimal place.

User ISa
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