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: Triangular numbers and v-t graph

  1. May 30, 2005 #1
    http://student.shcc.edu.hk/~s021107/phy.GIF [Broken]

    Displacement=area under v-t graph = 150m

    using another concept,
    the acceleration is 0.75m^s-2, so the displacement at

    total displacement =sum of displacement of every second
    Can you tell me wt's wrong here?
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. May 30, 2005 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Your link isn't working, but I assume you are describing uniformly accelerated motion starting from rest.

    Since [itex]v = at[/itex]:

    At t = 0s, the speed is 0 m/s
    At t = 1s, the speed is 1*.75 = 0.75 m/s
    At t = 2s, the speed is 2*.75 = 1.5 m/s, .... etc.

    To find the displacement during each second, use [itex]\Delta d = v_{ave} \Delta t[/itex], where the average speed equals [itex]v_{ave} = (v_i + v_f)/2[/itex]. Add these displacements and you'll find that they total to 150m.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook