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an athlete runs 300 m up a hill at a steady speed of 3.0 m/s. She then immediately runs the same distance at 6.0 m/s . What is her average speed for 600 m run?

User Varren
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1 Answer

6 votes

Answer:

4.0 m/s

Step-by-step explanation:

In the first part of the run, the athlete runs a distance of


d_1 = 300 m

at a speed of


v_1 = 3.0 m/s

So, the time he/she takes is


t_1 = (d_1)/(v_1)=(300)/(3.0)=100 s

In the second part of the run, the athlete covers an additional distance of


d_2 = 300 m

with a speed


v_2 = 6.0 m/s

So, the time taken in this second part is


t_2 = (d_2)/(v_2)=(300)/(6.0)=50 s

So, the total distance covered is

d = 300 m + 300 m = 600 m

And the total time taken

t = 100 s + 50 s = 150 s

Therefore, the average speed for the entire trip is


v=(d)/(t)=(600)/(150)=4.0 m/s

User Cppanda
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