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: Given a force equation and mass, find velocity

  1. Sep 26, 2014 #1
    1. The problem statement, all variables and given/known data

    The force on a particle of mass 3.0 kg moving in one dimension at time t, is given by:

    F = 9.0 +2.0t - 4.0t2. What is the velocity of the particle? (Let v0=0 and ti=0)

    2. Relevant equations

    I know to use F = ma for sure.

    And I believe this is the motion equation I should be using, but I'm not completely sure: v = v0 + at

    3. The attempt at a solution

    I substituted in the given equation for F and the given mass into Newton's 2nd Law equation and solved for the acceleration.

    I then further substituted in acceleration into the velocity equation and let v0 = 0 and t = 0, which just appeared to make the velocity 0 m/s which doesn't seem correct.

    Could someone point me in the correct direction?
  2. jcsd
  3. Sep 26, 2014 #2


    User Avatar

    Staff: Mentor

    Hi gwhite00. I see you are new here. http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif [Broken]

    F= ma
    can give you the acceleration vs time graph, then use integral calculus.

    Acceleration is not constant.
    Last edited by a moderator: May 7, 2017
  4. Sep 26, 2014 #3
    Thanks NascentOxygen for your quick reply.

    While I do know how to use integral calculus being in Calculus III, we are not actually using it in our class. So far my professor has only touched on derivational calculus.

    I know from previous problem sets written by this professor that his calculus based problems don't even up with a integer answer so I know that t will be part of my result.

    I'm just not sure if I'm using the correct equation of motion to achieve an answer of a velocity equation at time t as an answer.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted