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!

Did I do this question correctly?

  1. Sep 21, 2012 #1
    1. The problem statement, all variables and given/known data
    http://cyclotron.tamu.edu/dhy/sample_exam1_phys218.pdf [Broken]

    For Number 2 Part a


    2. Relevant equations
    v0 = 1.7 m/s
    F = ma
    v = 0m/s
    v² = v0² + 2aΔx


    3. The attempt at a solution
    Spent like 30 minutes trying to use a constant acceleration kinematics equation, but nothing seemed to work without knowing either the time or the acceleration.
    Then I remembered that F = ma, and the problem gave me the force (9.8*10^4N) and the mass (3.6*10^7kg). So I solved for a, and got -0.00272 m/s².

    I plugged this acceleration into v² = v0² + 2aΔx and solved for Δx, and I got 530.82 meters. Is this correct? If not, can anyone help me understand what I did wrong?
     
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. Sep 21, 2012 #2

    TSny

    User Avatar
    Homework Helper
    Gold Member

    Looks good!
     
  4. Sep 21, 2012 #3
    For C of that question, would I use the final velocity I obtained from part b as the new initial velocity, and 0 as the final velocity, solve for acceleration using v² = v0² + 2aΔx (Δx being 1.5m), and multiply that acceleration by the mass of the tanker?
     
  5. Sep 21, 2012 #4

    TSny

    User Avatar
    Homework Helper
    Gold Member

    That sounds good, too. Or, you could use work and energy concepts if you're familiar with them.
     
  6. Sep 21, 2012 #5
    Awesome; thanks. We haven't gotten to the work and energy stuff yet.
     
  7. Sep 21, 2012 #6

    TSny

    User Avatar
    Homework Helper
    Gold Member

    OK. Good work!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Did I do this question correctly?
Loading...