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!

Force problem

  1. Sep 30, 2007 #1
    1. The problem statement, all variables and given/known data

    A 2.75 kg object is moving in a plane, with its x and y coordinates given by x = 7t^2 - 4 and y = 5t^3 + 1, where x and y are in meters and t is in seconds. Find the magnitude of the net force acting on this object at t = 2.35 s.

    2. Relevant equations

    F=ma

    3. The attempt at a solution

    I took the 2nd derivative of each posn eqn and then substituted 2.35s for t to get accel; multiplied each accel by 2.75 kg to get Fx and Fy; then took the sqrt of (Fx^2 + Fy^2) to get magnitude.

    I am not sure how to proceed. Thanks for any help!
     
  2. jcsd
  3. Sep 30, 2007 #2

    Dale

    Staff: Mentor

    Write the answer down and turn the question in, you already got it.
     
  4. Sep 30, 2007 #3
    Thanks. I calculated the answer to be 104.5 N but it was marked as incorrect by the web program I use to turn in assignments. So something isn't right.
     
  5. Sep 30, 2007 #4

    Dale

    Staff: Mentor

    I got 198 N, you must've made an arithmetic error.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Force problem
  1. Force problem (Replies: 4)

  2. Forces problem (Replies: 3)

  3. Force Problem (Replies: 3)

Loading...