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: Vector prblem, HELP ME

  1. Jul 8, 2004 #1
    A jogger travels a route that has two parts. The first is a displacement A of 2.50 km due south, and the second involoves a displacement B that points due east. (a) The resultant displacement A+B has a magnitude of 3.75 km. What is the magnitude of B, and what is the direction of A+B relative to due south? (b) suppose that A-B had a magnitude of 3.75 km. What then would be the magnitude of B, and what is the direction of A-B realtive to due south?

    I have an answer for this problem I just want to know if it is right.
    (a)The magnitude of B is 2.80 km
    A+B points 48.188 degrees East of South

    (b)the magnitude of B is 2.80 km
    A-B points 48.188 degrees West of South
    Last edited: Jul 8, 2004
  2. jcsd
  3. Jul 8, 2004 #2


    User Avatar
    Science Advisor
    Homework Helper

    Looks pretty good. In finding the direction, I got the angle to be 48.190. Make sure you're not using rounded values, in fact you can just use cosX = 2.50/3.75, and solve for X (which is what I did). However, you should round to 3 significant digits, giving you 48.2 anyways, which would be the same using my number or yours.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook