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: Question re: constant velocity,zero acceleration

  1. Sep 8, 2006 #1
    I have a homework problem that I can't seem to figure out... Hope someone can help me...

    Runner A is initially 4.0 miles west of a flagpole and is running with a constant velocity of 6.0 mi/h due east. Runner B is initially 3.0 miles east of the flagpole and is running with a constant velocity of 5.0 mi/h due west. How far are the runners from the flagpole when they meet?

    I have looked at all of my equations, and I can't seem to find one that fits... Any help would be appreciated.

    Thanks!

    edit: I figured with the words "due west" and "due east" that the distance traveled is in a straight line with no slope... the part that's confusing me is the "part where they meet"... I used the average speed = distance/time and found runner B to be arriving at the flagpole ahead of runner a.... so, i assume that the point that they meet will be west of the flagpole... that's about where my brain stops working :)
     
    Last edited: Sep 8, 2006
  2. jcsd
  3. Sep 8, 2006 #2
    I would appreciate any help if someone can just steer me in the right direction.... please!!!

    Thanks again.
     
  4. Sep 8, 2006 #3

    Astronuc

    User Avatar
    Staff Emeritus
    Science Advisor

    Do the runners start at the same time?

    For each runner x = xo +/- v*t, where t is the time (duration) of the running. If the runners start at the same time and end at the same time, then they travel during the same period.

    Take west as -x and east at +x. Running west, mean -v and running east means +v.

    Determine the point at which they meet, and that should give the distance with respect to the flagpole (x=0). If x=-1mi, then the runners are west of the flagpole by one mile.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook