1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

Quesiton on Newtons Second Law, Need Help.

  1. Mar 18, 2009 #1
    Two blocks of identical material(Block1 20kg, Block2 10kg) are connected by a light rope on a level surface. An applied force of 55Nright causes the blocks to accelerate. While in motion, the magnitude of the force of friction on the block system is 44.1N.

    2. Relevant equations
    a)Calculate acceleration of the blocks
    b)The force of friction on the 10kg block has a magnitude of 14.7 N, calc the tension in the rope connecting the two blocks.

    3. The attempt at a solution
    I found "a" by using:
    10.9N=30kg x a
    a=0.36 m/s^2

    For "b"

    Book says the right answer is 37N. I just wanna know how its 37N.

    I need to understand solving tension problems, I have a test 2morrow.

    Thanks :)
    Last edited: Mar 18, 2009
  2. jcsd
  3. Mar 19, 2009 #2


    User Avatar
    Homework Helper

    Hi yunuscanemre,

    Your answer here would be correct if there were no acceleration, because then you would need all of the forces to cancel. However, there is an acceleration here, and so you need to account for that in your equation. Do you see what to do now?
  4. Mar 20, 2009 #3
    thanks I get :))))
  5. Mar 20, 2009 #4


    User Avatar
    Homework Helper

    Glad to help!
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Quesiton Newtons Second Date
Charged pendulum in magnetic field Saturday at 12:36 PM
Semiconductor diode (graph quesiton) Mar 31, 2014
Hard physics quesiton Jan 9, 2014
Pulley quesiton Mar 23, 2013
Circuit Quesiton Sep 10, 2012