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: Intergal? work done by a non constant force

  1. Oct 8, 2009 #1
    1. The problem statement, all variables and given/known data
    A force F = (4.38 x i + 2.84 y j) N acts on an object as it moves in the x direction from the origin to x = 5.52 m. Calculate the work done on the object by the force.

    2. Relevant equations
    intergal of F from 0 to 5.52m

    3. The attempt at a solution

    not sure if im suppose to intergrate, or what im supposed to do to start the process
  2. jcsd
  3. Oct 8, 2009 #2
    [tex]W=\int\limits_{x=0}^{x=5.52}\vec{F}.{\rm d}\vec{x}[/tex]

    where [tex]\vec{x}=x\vec{i}[/tex] is the position vector.
  4. Oct 8, 2009 #3
    ok so u intergrate the sum of X and Y right?
  5. Oct 8, 2009 #4
    Not exactly. By the looks of the problem, the object only moved in the x direction. So there is no net work in the y-direction. You only integrate the x-component.
  6. Oct 8, 2009 #5
    So then it would be the intergal of 4x?
  7. Oct 8, 2009 #6

    [tex]{\rm d}\vec{x}={\rm d}x \vec{i}[/tex]


    [tex]\vec{F}.{\rm d}\vec{x}=\left(4.38x \vec{i}+2.84y \vec{j}\right). \vec{i} {\rm d}x=4.38x{\rm d}x[/tex]

    [tex]W=\int\limits_0^{5.52} 4.38x{\rm d}x[/tex]
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook