SOLUTION: This is an Algebra 1 question: David rode his bike east at 20 mi/hr for 36 min with a tailwind. He then turned around to ride home along the same route against the wind. If the re

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Question 1066369: This is an Algebra 1 question: David rode his bike east at 20 mi/hr for 36 min with a tailwind. He then turned around to ride home along the same route against the wind. If the return trip took 45 min, find the wind speed and the speed at which David pedals with no wind (to the nearest mile per hour). Thank you so much on this! I not only need the answer but HOW it was solved.
Found 3 solutions by josgarithmetic, ikleyn, Alan3354:
Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
                   SPEED        TIME       DISTANCE

WITHWIND           20           36%2F60          d

AGAINSTWIND        r-w          3/4          d


You can find distance with the wind, d, and then use it in finding r or w.

20%2836%2F60%29=d

20%286%2F10%29=d

%282%2A6%29=d

d=12

Note also, r%2Bw=20. This is the given rate WITH THE TAILWIND.

The AGAINST Wind situation gives %28r-w%29%2A%283%2F4%29=12, so a possible system in unknowns r and w is
system%28%28r-w%29%283%2F4%29=12%2Cr%2Bw=20%29
Uncomplicated to solve for r and w.

Answer by ikleyn(52884) About Me  (Show Source):
You can put this solution on YOUR website!
.
Hey,

when the person rides bicycle against the wind,  his speed IS NOT the difference of the rates  u-v.

When the person rides his bicycle tailwind,  his speed IS NOT the sum of the rates  u + v.

Therefore, this problem formulation IS FULL NONSENSE from the Physics point of view.

Do not refer to Algebra-I.   IT IS NOT ALGEBRA-I question.
It is somebody's very bad fantasy like the film  "IDIOCRACY".
It is TOTAL NONSENSE from the beginning to the end.

You will not find a textbook in ALGEBRA-I with such an idiotic problem.

The solution by "josgarithmetic" does not add sense to this nonsense.


    PLEASE   DO   NOT   SEND   SUCH   A   NONSENSE  TO   THIS   FORUM  ! ! ! ! ! ! !


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If I see a smallest mention on this subject, I will annihilate that post immediately, without any explanations !



Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
The speed of a bicycle is not linearly related to windspeed.
If the wind blows from the right side, it doesn't cause a bicycle to change its direction.
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It's another instance of people writing math problems and books who do not know what they're talking about.
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If the relation between bike speed and windspeed is defined it would be a viable problem. The wind effects are likely a function of the square of the relative windspeed, but it's not up to anyone to assume that.
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The solution by another tutor would apply to airplanes and to boats, but not to bicycles, walking, running, or roller skating.