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 and free fall problem

  1. Nov 10, 2009 #1
    1. The problem statement, all variables and given/known data
    A jumbo jet needs to reach a speed of 300 km/hr on a runway for take off. Assuming a constant acceleration and a runway 2 km long, what minimum acceleration from rest is required to get the jet in the air?

    2. Relevant equations
    I tried using the equation:

    But there is also:

    3. The attempt at a solution
    I set up the following variable list:
    Xo=1.5 Vo=?
    X=21.5 V=0
    t=? a=-9.8

    I plugged these values into the equations mentioned above to get a final answer of 2250km/hr^2 for the acceleration needed.
    Last edited: Nov 10, 2009
  2. jcsd
  3. Nov 10, 2009 #2
    The first equation you have written (Vf^2 - Vi^2 = 2*a*x) should work. Assume the plane is starting from rest. This will give you all the variables except for the one you're looking for.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook