Question 965093: In still water, Jacob's sailboat cruises at 16.5 km/h. On the river near their cottage, the boat travels faster downstream than upstream, because of the current. The boat takes 5 hours for a trip upstream but only 2 hours to do the same distance on the return downstream. Determine the speed of the current by jacobs cottage
Found 2 solutions by josgarithmetic, lwsshak3:
Answer by josgarithmetic(39618)   (Show Source):
You can put this solution on YOUR website! r, boat speed when no river current
c, speed of river current
u, time upstream
v, time downstream
d, the one-way trip distance
RT=D for rate time distance relationship
____________________rate____________time__________distance
UPSTREAM____________r-c_____________u____________(r-c)*u=d
DOWNSTREAM__________r+c_____________v____________(r+c)*v=d
Solve for c.
Answer by lwsshak3(11628) (Show Source):
You can put this solution on YOUR website! In still water, Jacob's sailboat cruises at 16.5 km/h. On the river near their cottage, the boat travels faster downstream than upstream, because of the current. The boat takes 5 hours for a trip upstream but only 2 hours to do the same distance on the return downstream. Determine the speed of the current by jacobs cottage.
***
let c=speed of current
16.5+c=speed of sailboat downstream
16.5-c=speed of sailboat upstream
travel time*speed=distance
..
2(16.5+c)=5(16.5-c)
33+2c=82.5-5c
7c=49.5
c=7.07 km/h
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