To find the time we can simply do unit analysis to get the time in seconds then convert that into minutes.
We can flip 3.4m/s to get seconds on the top
1s/3.4m × 5600m = 5600ms/3.4m = 1647s
to turn seconds into minutes:
1646s × (1 minute ÷ 60s) = 27.45 minutes = 27.5 minutes