Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

?
Lv 6
? asked in Science & MathematicsMathematics · 9 years ago

Cargo and Passenger Planes Trivia?

A cargo plane flying at average speed of 750 miles per hour leaves station B East bound at 1 AM local time and reaches station A at 11 AM local time. A passenger plane leaves station B at 6 AM

local time and flying at average speed of 900 miles per hour lands at station A at 7 AM same day.

(a) What is the distance between places A and B

(b) What is the difference in local times between these 2 places.

(c) At what distance from station A the planes would cross each other?

Clue: Time difference between the two stations is 4 hours. Can you solve the problem without clue.

How?

1 Answer

Relevance
  • 9 years ago
    Favorite Answer

    S=distance between A and B

    X=time different between A and B, where A is x hour ahead B, if x is negatif, it will means the opposite

    So, when B is 1 o'clock, A is 1+x o'clock

    Tc: cargo flying time = 11-1-X = 10-x

    Tp: passenger flying time = 7-6+X = 1+x

    S = Tc x cargospeed = Tp x passenger speed

    (10-x) 750 = (1+x) 900

    7500 - 750x = 900 + 900x

    7500-900 = 900x + 750x

    6600 = 1650x

    x = 4

    Time difference 4 hours

    S = (10-x)750 = (10-4) 750 = 6x750 = 4500 miles

    Crossing place is n miles from A, so

    t = n/900

    and also

    t = (4500-n)/750

    n/900 = (4500-n)/750

    750n = 4050000 - 900n

    750n + 900n = 4050000

    1650n = 4050000

    n = 2454 miles from A

Still have questions? Get your answers by asking now.