Question

A runner moving through a 1600 m course takes 5 minutes and 25 seconds to go 1230 m. What must his average velocity be for the remainder of the course if his average velocity for the whole race was 3.81 m/s

Answer 1

Answer:

3.89 m/s

Explanation:

If we want an average velocity for the whole race of 3.81 m/s in a 1600 m course, the course it must be completed in:

$\frac{1600 \ m}{3.81 \ \frac{m}{s} } = 420 \ s$.

So, the runner already run for 5 minutes and 25 seconds, this is

$5 \ min *60 \ \frac{s}{min} + 25 \ s = 325 \ s$.

For finishing the course, the runner has

$420 \ s - 325 \ s = 95 \ s$.

Now, the distance that the runner has to cover in this time its:

$1600 \ m - 1230 \ m = 370 \ m$

Finally, the runner average velocity for the remainder will be:

$V= \frac{distance \ left}{time \ left} = \frac{370 \ m}{95 \ s} = 3.89 \ \frac{m}{s}$