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!

Finding instantaneous velocity of objects in projectile motion

  1. Mar 16, 2008 #1
    1. The problem statement, all variables and given/known data
    No air resitance
    Initial speed 8 m/s
    inst. time at 3 s

    Find instantaneous velocity at 3s.

    Components of displacement:
    dx= 24
    dy= 44


    2. Relevant equations

    d=v1t+(1/2)a(t)^2 or other kinematics equations

    3. The attempt at a solution

    I tried to find the components of the velocity using the components of the displacement (d/t=v). But both my answer and angle of direction were wrong. How do i do this?
     
  2. jcsd
  3. Mar 16, 2008 #2

    rock.freak667

    User Avatar
    Homework Helper

    So dx and dy are those values at t=3?
    If so consider Vertical motion:
    [itex]s=ut+\frac{1}{2}at^2[/itex]

    where u is the initial vertical velocity. Sub t=3 in there and get u. and well you know how to get the horizontal component (v=d/t as you stated before)
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?