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!

Homework Help: Acceleration Problem

  1. Aug 23, 2007 #1
    1. A plane traveling at 10km/hr lands on an aircraft carrier and stops in 25.0m
    A. Find the acceleration in m/s^2
    B. Find the time it took to stop in seconds

    2. Relevant equations
    1km/hr = .278 m/s

    3. The attempt at a solution
    100(.278)= 27.8 m/s
    A. 25-27.8 = 2.8 m/s
    B. 8.92 seconds (25/2.8)

    Is this anywhere near correct? something seems wrong.
  2. jcsd
  3. Aug 23, 2007 #2


    User Avatar
    Homework Helper

    When you converted to m/s you used 100km/h instead of 10km/h.

    I don't understand how you did part A and B... seems like you're mixing up distance, speed and acceleration.

    Remember the plane is undergoing a constant deceleration (or a negative acceleration) and coming to a stop over 25m.

    Part A and B involve direct use of kinematics equations... you should have studied these... Can you think of a kinematics equation you can apply in part A? You're trying to find acceleration... you know the distance, the initial velocity, and the final velocity. There's an equation you can use.
  4. Aug 23, 2007 #3


    User Avatar
    Science Advisor
    Homework Helper

    Not near correct. 27.8 m/s is ok, though. Consider using kinematic equations like x(t)=x0+v0*t+(1/2)*a*t^2 and v(t)=v0+a*t. Can you start the problem?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook