About Chanda Walker Expertise I can answer word problems involving mathematics at the high school and college level. I particularly enjoy calculus word problems. Please don't just type the math problem without comments. If you don't tell me what problem your having, I can't help.
Experience Have done word problems as a tutor and as a student of mathematics and physics for years.
Organizations Sigma Xi
Education/Credentials Optical Science PhD
Past/Present Clients I've answered hundreds of questions here at AllExperts.com in algebra, physics and general math sections.
Question QUESTION: I can't understand how to set up this problem. What am I missing in setting it up. A six-passenger plane cruises at 180 mph in calm air. If the plane flies 7 miles with the wind in the same amount of time as it flies 5 miles against the wind, then what is the wind speed?
ANSWER: I'll set it up only, because that seems to be what you need but let me know if you still need help. I'm happy to do that.
note: the units of mph can be written as m/h
v = 180
5/(v - ws) = time Unit analysis: m/(m/h)= h
7/(v + ws) = time
5/(v - ws) = 7/(v + ws)
5*(v + ws) = 7*(v- ws)
Hopefully it will be easy from here but if not . . . I'll be around.
---------- FOLLOW-UP ----------
QUESTION: If I worked this correctly, the answer is the wind speed is 180 miles per hour. Is that correct? If not, please show me what I missed.
Answer Yikes! That is a lot of wind! That is the speed of the airplane not the wind I think.
5v + 5ws = 7v - 7ws
12ws = 2v
ws = v/6
ws = 30
I think 30 mph sounds more reasonable. Did you worked it like this:
5v + 5ws = 7v - 7ws
2ws = 2v (you subtracted the 7ws across maybe???)
ws = v
