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!

Distance and speed

  1. Sep 8, 2009 #1
    1. The problem statement, all variables and given/known data

    A mortorist travels 80km at 100 km/h, and 50 km at 75 km/h. WHat is the average speed for the trip?

    2. Relevant equations
    I used (avg)s=distance/time

    3. The attempt at a solution
    I got 6.2 km/h which I know is way off.
  2. jcsd
  3. Sep 8, 2009 #2
    It's a good first step to realize that your answer is not terribly realistic.

    I believe you have the right equation. The average speed is: d/t. What is the total distance travel (d=???)? The little trick will be to find out how long it took the motorist to travel this distance (t=???)?

  4. Sep 8, 2009 #3
    [tex]v_{avg}=\frac{\Delta x }{\Delta t}[/tex]
    Find how far it travels in part one and add that to how far it travels in trip 2. And do the same for t.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Distance and speed
  1. Speed and distance (Replies: 1)

  2. Distance and speed (Replies: 9)