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!

Challenging Vector Problem

  1. Jan 30, 2008 #1
    ******Challenging Vector Problem******

    Two beetles run across flat sand, starting at the same point. Beetle 1 runs 0.50 m due east, then 0.82 m at 26° north of due east. Beetle 2 also makes two runs and the first is 1.6 m at 43° east of due north.
    (a) What must be the magnitude of its second run if it is to end up at the new location of beetle 1?
    Answer in m

    (b) In what direction must it run?
    Answer in ° (counterclockwise from due east)

    I have made numerous attempts to the problem here is one of my attempts

    Vector A =.50 i + 0 j
    Vector B = .82 cos26 i + .82 sin26 j = .7370 i + .3594 j
    Vector C = 1.6 cos43 i + 1.6 sin43 j = 1.1701 i + 1.0911 j

    I did A+B - C and that was R = .0669 i + (-.7317) j
    |R| = .7347m and angle = 84.77

    What am i doing wrong when i plug the answers online it says i'm wrong! Please please help me on this. Can you please provide the exact answer along with the meathod i want to see the whole thing done...
    Thanks in advance.
  2. jcsd
  3. Jan 30, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Note that "north of due east" is different from "east of due north".
    Draw in the angle in both cases... then look at your components.
  4. Jan 30, 2008 #3
    It's still unclear to me, despite my several attempts i am unable to solve it. Please help help help!!!!
  5. Jan 30, 2008 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    The angle given for beetle 2 is measured off of "north." Your calculations are set up as if the angle is measured off of "east."

    Use the angle that beetle 2 makes with "east" instead of "north."
  6. Jan 30, 2008 #5


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    I think vector B is correct but Vector C is wrong.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Challenging Vector Problem Date
How to find the radii of these 2 circles given 2 known points Jun 19, 2017
I Need Difficult Questions! Nov 28, 2016
Need challenging vector problems Sep 10, 2005