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!

Simple Uniform Motion Problem

  1. Oct 21, 2015 #1
    1. The problem statement, all variables and given/known data
    Marlene rides her bicycle to her friend Jon's house and returns home by the same route. Marlene rides her bike at constant speeds of 6 mph on level ground, 4 mph when going uphill, and 12 mph when going downhill. If her total time riding was 1 hour, how far is it to Jon’s house?

    Answer = 3 miles

    2. Relevant equations
    d=rt
    t=d/r

    3. The attempt at a solution

    t1+t2+t3=1hour

    L/6mph+U/4mph+D/12mph=1hour

    I have tried solving for each variable independently and then substituting it, but when I do that all my terms cancel out and I am either left with 1=1 or 12=12 depending of which equation I start with.

    I understand that Marlene traveled different distances at different rates, and for different intervals of time. I know that the total distance traveled in 1 hour must be 6 miles but I can't seem to express it mathematically.
     
  2. jcsd
  3. Oct 21, 2015 #2

    SteamKing

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    If Marlene travels a certain distance uphill on her way to Jon's house, does she travel this same distance uphill on her way back home?
     
  4. Oct 21, 2015 #3
    She would travel the same distance, but she will be going downhill where ever she initially traveled uphill.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Simple Uniform Motion Problem
Loading...