Answer:
560 kg m/s
Explanation:
First of all, we have to find the velocity of the runner, which is given by the ratio between the distance covered (400 m) and the time taken (50 s):
[tex]v=\frac{d}{t}=\frac{400 m}{50 s}=8 m/s[/tex]
And now we can calculate the average momentum of the runner, which is equal to the product between the mass of the runner (70 kg) and its velocity, that we have previously calculated:
[tex]p=mv=(70 kg)(8 m/s)=560 kg m/s[/tex]
