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!

Physics magnitude and direction?

  1. Sep 3, 2015 #1
    I know this is basic stuff, but if anyone would be willing to help... :)
    At a certain time, a car is 150 meters due west of your house. If it is traveling with a constant velocity of 30m/s 30 degrees south of east, what are the ,magnitude and the direction of its position relative to your house 5 seconds later?


    150cos30= roughly 130 m



    tan inverse(75/20)= 75 degrees

    So, the car is 77.6 meters away from the house at an angle of 75 degrees, south of west.

    Does that seem correct?
  2. jcsd
  3. Sep 3, 2015 #2


    User Avatar
    Homework Helper
    Gold Member

    Welcome to PF!

    Your answer and method of solution look correct to me.
  4. Sep 4, 2015 #3
    Thanks! :)
    Though, should it be inverse tan (20/75)=15 degrees in the last part because the answer in the book was 15° west of south?
  5. Sep 4, 2015 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    Yes, tan-1(20/75) ≈ 14.93° .
  6. Sep 4, 2015 #5


    User Avatar
    Homework Helper
    Gold Member

    75o south of west is the same as 15o west of south. So, either way of expressing the answer is fine.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Discussions: Physics magnitude and direction?