Answer:
1.56
Explanation:
Let man run at constant speed =r m/s
Constant speed of side walk=s m/s
When the man running in the direction as the side walk is moving, then the relative speed =r+s m/s
When the man running in opposite direction as the side walk is moving=r-s m/s
Time taken when he run along a moving sidewalk from one end to the other=2.6 s
Time taken when he ran back along the side walk to his starting point=11.9 s
We have to find the ratio of the man's running speed to the side walk's speed.
Suppose the, length of sidewalk=d
Distance=[tex]speed\times time[/tex]
[tex]d=(r+s)\times 2.6[/tex]
[tex]d=(r-s)\times 11.9[/tex]
[tex]2.6r+2.6s=11.9r-11.9s[/tex]
[tex]2.6s+11.9 s=11.9 r-2.6 r[/tex]
[tex]14.5 s=9.3 r[/tex]
[tex]\frac{r}{s}=\frac{14.5}{9.3}[/tex]
[tex]\frac{r}{s}=1.56[/tex]
