Irodov Problem 1.100

a) From (1) it is clear that the boat will never completely stop, it will stop only after infinite time.
b) From (2) by setting v=0 (the time when the boat stops) we can find the distance covered as,
c) the time average of velocity (mean velocity) can be evaluated by . If the the velocity decreases time then from (1) we have


Now we can calculate the mean velocity as,