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: Stuck on this problem

  1. Sep 22, 2004 #1
    A rock of mass 33 kg accidentally breaks loose from the edge of a cliff and falls straight down. The magnitude of the air resistance that opposes its downward motion is 239 N. What is the magnitude of the acceleration of the rock?

    I tried a=239*33 and I got 7.24 but that was wrong. Please help. I don't know what else to do.
  2. jcsd
  3. Sep 22, 2004 #2


    User Avatar
    Homework Helper

    What are the forces acting on the block?

    What does newton's 2nd law state?
  4. Sep 22, 2004 #3
    Did you draw a free body diagram of the falling rock including all forces acting upon the rock?

    Did you write out [itex]\sum \vec F=m\vec a[/itex]? I'm sure if you do the above and sum the forces you'll get the correct answer.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook