The speed of the river flow is 0.5 m / s in what time the raft floating along the current will pass 0.5 km.

Given:

Vreki = 0.5 meters per second – the speed of the river;

S = 0.5 kilometers = 500 meters – distance.

It is required to determine how long t (seconds) the raft will cover the distance S.

According to the condition of the problem, the raft floats along the river, that is, it will move at the speed of the river. Then:

t = S / Vreki = 500 / 0.5 = 1000 seconds (approximately 16.7 minutes).

Answer: the raft will cover the distance of 0.5 kilometers in 1000 seconds (approximately 16.7 minutes).