1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
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: A plane flies 457 km east from city A to city B

  1. Jun 15, 2008 #1
    1. The problem statement, all variables and given/known data

    A plane flies 457 km east from city A to city B in 41.0 min and then 949 km south from city B to city C in 1.30 h. For the total trip, what are the (a) magnitude (in km) and (b) direction of the plane's displacement, the (c) magnitude (in km/h) and (d) direction of its average velocity, and (e) its average speed (in km/h)? Give your angles as positive or negative values of magnitude less than 180 degrees, measured from the +x direction (east).

    3. The attempt at a solution

    Part A

    457cos(0) + 949sin(270)

    = 457i + -949j
    R=1053.3 km

    Part B

    arctan(-949/457) = -64.29 degrees

    I am not sure if either of those are correct and as for the rest of the problem I need help on how to solve for those things.
  2. jcsd
  3. Jun 15, 2008 #2
    Never mind everyone I finally got it

    (c) Average velocity = Total displacement/total time
    = 1053 km/(41+78)/60 = 530.9 km/h
    (d) Direction is the direction of displacement; - 64.3 degrees

    (e) Average speed = total distance/total time
    = (457 + 949) km/1.9833 h = 709 km/h
  4. Jun 15, 2008 #3
    You have the distance traveled and the time for each direction can't you calculate the velocity of each vector?
  5. Jun 15, 2008 #4
    yea I got it now thanks for your help
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook