1. Not finding help here? Sign up for a free 30min 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!

Finding distance from origin using acceleration

  1. Oct 19, 2015 #1
    1. The problem statement, all variables and given/known data
    Acceleration of a particle that begins at rest at the origin is given by a(t)=3ti+4tj, where a is in m/s^2 and t is in seconds. The particle's distance from the origin at time t=2s is what?

    2. Relevant equations
    You need to find velocity then distance

    3. The attempt at a solution
    To find velocity I integrated the acceleration (I haven't covered integration in calculus yet, so it's a bit difficult to do). I got v(t)=(3t^2)/2i+2t^2j. Now to find distance I integrate velocity. I got x(t)=(t^3)/2i+(2t^3/3)j. Plugging in t=2 s, I get x=9.33 m. But my teacher says the answer is about 7 m.
     
  2. jcsd
  3. Oct 19, 2015 #2

    gneill

    User Avatar

    Staff: Mentor

    You did fine with your integrations! But note that the result is a vector value with i and j components (or x and y components if you wish). How do you find the magnitude of a vector?
     
  4. Oct 19, 2015 #3
    You would do the square root of the i and j hats right?
     
  5. Oct 19, 2015 #4
    And thank you for your response.
     
  6. Oct 19, 2015 #5

    gneill

    User Avatar

    Staff: Mentor

    Square root of the sum of the squares. Like finding the hypotenuse of a right angle triangle. This is also called "adding in quadrature" if you're interested in the lingo.
     
  7. Oct 19, 2015 #6
    Thank you man. I found the distance by finding the i and j hat separately. I got 4ti+(16/3)tj m. I plus in t=2 s and I get square root of 44.4. which is about 6.67 which is close to 7 m. Thanks a lot for helping me.
     
  8. Oct 19, 2015 #7
    You already know I'm interested in the lingo.
     
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: Finding distance from origin using acceleration
Loading...