A river boat travels from port A to port B, a distance of 15.0 km downstream, in 1 hour 40 minutes. The return journey takes 2 hours 30 minutes. Calculate: (a) the boat speed relative to the water? (b) the speed of the river?
1 Answer
A.
B.
Explanation:
Speed =
Downstream:
Speed
Speed
Upstream:
Speed
Speed
The boat's speed relative to the water is equal to the average of its two speeds, so
The river's speed is the difference between the boat's relative speed and its actual speed, so
Now, using dimensional analysis, you can convert
and the boat's speed is