Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Distance calculation (right triangle)

  1. Jan 28, 2007 #1
    1. The problem statement, all variables and given/known data
    Starting from city A, a car drives 250 miles east to city B, then 300 miles north to city C, and then 700 miles west to city D. What is the distance between city A and city D? (Points: 1)
    300 mi
    400 mi
    500 mi
    600 mi

    2. Relevant equations
    A^2 + B^2 = C^2

    3. The attempt at a solution

    A^2= 300^2
    B^2= (700-250)^2
    C^2= 292500
    C= 540.8 miles.
    Which answer should I choose? 500 or 600?

    Thanks!
     
  2. jcsd
  3. Jan 28, 2007 #2

    radou

    User Avatar
    Homework Helper

    Are you sure these are the listed answers?
     
  4. Jan 28, 2007 #3
    Yes, did you get the same result I did?... Maybe it has something to do with significant figures?...
     
  5. Jan 28, 2007 #4

    radou

    User Avatar
    Homework Helper

    Your calculation is correct. The offered answers are obviously wrong. Mistakes happen. :wink:
     
  6. Jan 28, 2007 #5
    I will ask the professor.
    Thanks anyway!
     
  7. Jan 28, 2007 #6
    I think that the answer is 500. He might count 300 and 700 to only have 2 significant figures, as opposed to 300. and 700. which have 3. Therefore, if the answer is 540, it would only be 500 if we take this into consideration... I think.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook