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!

Mechanics problem

  1. Mar 6, 2010 #1
    1. The problem statement, all variables and given/known data
    Car A, which is travelling at a constant velocity of 15 ms-1, passes Car B, which is stationary, at time t = 0. At the instant that it is being passed, Car B begins to move, accelerating at a constant rate of 0.1 ms-2 in the direction in which Car A is travelling. At what speed will Car B be travelling as it passes Car A (in ms-1)?

    2. Relevant equations

    3. The attempt at a solution
    Ok so I know that this is a relative velocity question? so the relative velocity will decrease by 0.1 per second. But I then get stuck, im having trouble understanding the situation I think]

  2. jcsd
  3. Mar 7, 2010 #2
    Do you know the Kinematics Equations?


    You need to find the right equation which will find the speed of the car in question as a function of time. Then you find the point where the displacement of both cars is equal, and calculate for the speed.

    Alternatively, you could draw a graph and plot the displacement of the cars against time. That way, the speed of the car will be dx/dt at the point that they cross.
    Hope that helps
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook