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: Physics Kinematic Problem - need help

  1. Jun 21, 2005 #1
    Physics Kinematic Problem -- need help

    Well here I am studying for the final and this question pops up and I have no idea how to do it. I know the answer however, but it does not realy help me.

    If you walk 6.0 km in a straight line in a direction north of east and you end up 2.0 km east and several kilometers north. How many degrees north of east have you walked?


    a) 19 degrees
    b) 45 degrees
    c) 60 degrees
    d) 71 degrees

    Answer: d

    Thank you for your help
  2. jcsd
  3. Jun 21, 2005 #2
    The trig to this is to try drawing the walk on a piece of paper.
  4. Jun 21, 2005 #3


    User Avatar
    Science Advisor

    Did you draw a diagram? I drew a triangle with a vertex at the origin and the hypotenuse going north and east (up and to the right) for 6 units. The opposite side would be 2 units....Can you finish from there?
  5. Jun 21, 2005 #4
    would it be possible to draw it in the forum?? I still don't get it. I knew how to do this a while ago and it was pretty easy. I did draw a diagram but it didn't really help for some reason. Maybe I read the question wrong, but either way I still don't understand. :cry:

    AH HA!! Thanks Fred. When you said 'opposite' I thought it meant opposite side of the plane. Ah it means the opposite side. Ok thanks I get it.

    Cos -1 (2/6) = 71


    Thanks again
    Last edited: Jun 21, 2005
  6. Jun 22, 2005 #5
    This is simple. First you walk 6km north of east, you end up 2km east and some km's north . Draw a triangle representing the above values where base=2 and hypotenuse=6


    [itex]cosQ= \frac{1}{3}[/itex]
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook