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!

Classic Mechanics problem.

  1. Jan 11, 2009 #1
    1. The problem statement, all variables and given/known data
    As soon as a traffic light turns green, a car speeds up from rest to 51.0 mi/h with constant acceleration 8.00 mi/h-s. In the adjoining bike lane, a cyclist speeds up from rest to 29.0 mi/h with constant acceleration 12.50 mi/h-s. Each vehicle maintains constant velocity after reaching its cruising speed.
    (a) For what time interval is the bicycle ahead of the car?
    (b) By what maximum distance does the bicycle lead the car?

    2. Relevant equations

    Constant acceleration equations specifically xf=xi+vxi*t+1/2*ax*t^2

    3. The attempt at a solution
    13.08 seconds as the answer to part A. by finding at what time the velocities are maxed out which is 2.32 and 6.75, respectively the bike and car. After this I set the xf of each equal to each other and solve for t. Any help?
    Last edited: Jan 11, 2009
  2. jcsd
  3. Jan 12, 2009 #2
    A speed/time graph is always a useful tool.

    The maximum distance will be when the car reaches the same speed as the bicycle's maximum speed, that is when the bicycle is no longer pulling away from the car.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Classic Mechanics problem.