SOLUTION: Hi, here's my question: Charlie rows at a constant speed downstream in the river from Amaroo to Bradden in 3 hours and back upstream in 4 hours. Assume the river flows at a cons

Question 982496: Hi, here's my question:
Charlie rows at a constant speed downstream in the river from Amaroo to Bradden in 3 hours and back upstream in 4 hours. Assume the river flows at a constant rate. Find the number of hours it would take a piece of driftwood to float downstream from Amaroo to Bradden.
Thank you so so much for your help! :D
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Charlie has a speed due to his rowing and the current,
but the driftwood only has speed due to the current
Let = Charlie's speed without the current
Let = the speed of the current
= Charlie's speed going downstream
= charlie's speed going upstream
Let = distance from Amaroo to Bradden in km
----------------------------------------------
Equation for going downstream:
(1)
Equation for going upstream:
(2)
----------------------------
Plug (1) into (2)
(3)

--------------
Add (1) and (2)

--------------------
It takes 24 hrs for the driftwood to float downstream
check:
(1)
(1)
(1)
(1)
(1)
and
(2)
(2)
(2)
(2)
(2)
OK
Hope I got it!

RELATED QUESTIONS
Hi, here's my question: Charlie rows at a constant speed downstream in the river from... (answered by macston)

A student rows at a constant speed (relative to the water) downstream in the Nambucca... (answered by ikleyn)

a man rows his boat up a river at a constant speed when opposite a cabin on the shore,... (answered by ankor@dixie-net.com)

A man can row at 6km/h in still water. He rows 8km up a river and then back again, taking (answered by jorel1380)

Michael rows downstream on a river. He then returns to the starting point. He traveled... (answered by lwsshak3)

jonathan and samantha paddle their canoe 26 miles downstream in 2 hours. after picnic... (answered by ankor@dixie-net.com)

26.Solve. 15t^2 + 7t = 2 Solve:#14 Rowing. Abby rows 10 km upstream and 10 km... (answered by Alan3354,solver91311)

Brian decides to start training for swimming in a river.��The current in the river is... (answered by jim_thompson5910)

Hi would you please help me solve my homework problem. A paddle boat can move at a... (answered by lwsshak3)