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: Problem on One-Dimentional Motion: Bullet going through a board.

  1. Sep 25, 2008 #1
    An indestructible bullet 2.00cm long is fired straight through a board that is 10.0cm thick. The bullet strikes the board with a speed of 420 m/s and emerges with a speed of 280m/s.
    (a) What is the average acceleration of the bullet through the board?
    (b) What is the total time that the bullet is in contact with the board?
    (c) What thickness of board (calculated to 0.1cm) would it take to stop the bullet, assuming that the acceleration through all boards is the same?

    We can use these equasions (v0=initial velocity, D=displacement):

    v = v0 + at
    D = v0t + (1/2)at2
    v2 = v02 + 2aD
    D = (1/2)(V0+V)t
    D = vt - (1/2)at2

    I have found that the answer to part (a) is equal to -490,000m/s2,
    but I cannot figure out how to do parts (b) and (c).
    Please help?!
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted