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Homework Help: Vector Addition: Finding Displacement

  1. Oct 30, 2011 #1
    I am having a lot of trouble with my homework. If anyone could help me, it would be much appreciated.

    The Smith's go on vacation. They travel 16.0 km north/west; then turn 27 degrees to the left and go 135 km; then 294 km south/west. What is their displacement from home?

    So I found the X and Y components (using trig functions) of each vector and added them. I then tried to put those numbers into the Pythagorean theorem, but it's not working. I think my X and Y components are wrong. I got the Xs to equal 69 and the Ys to equal 155.3. This is the diagram I made: (the numbers that were given are in red, the rest I found, not sure if they are right though)
    [PLAIN]http://img257.imageshack.us/img257/7742/78747381.png [Broken]
    By c42711 at 2011-10-30
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Oct 30, 2011 #2


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    Homework Helper

    Yes, something wrong with those x y components. The 294 SW vector has x component 294*cos(45) = 208 west. So your total of 69 is way too small. Got your calculator set on degrees? Note that two of the y components are north while the third one is south.
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