1. Not finding help here? Sign up for a free 30min 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!

Tension between two sliding blocks

  1. Sep 16, 2014 #1

    END

    User Avatar

    1. The problem statement, all variables and given/known data

    The problem:

    gUEoZ.jpg

    Two blocks made of different materials connected together by a thin cord, slide down a plane ramp inclined at an angle θ to the horizontal as shown in the figure (block B is above block A). The masses of the blocks are mA and mB and the coefficients of friction are μA and μB.

    If mA=mB=5.5kg, and μA = 0.19 and μB = 0.30, determine the tension in the cord, for an angle ##θ = 28^{\circ}##

    2. Relevant equations

    Newton's Laws

    3. The attempt at a solution

    My Attempt:


    After setting up free body diagrams (not shown), I found the acceleration ##a\approx2.5~\frac{m}{s^2}## along with the following equation for T:

    $$sin(\theta )mg-T-\mu _acos(\theta)mg=ma$$

    $$\Rightarrow T=m(sin(\theta)g-\mu _acos(\theta)g-a)\Rightarrow$$

    ##T\approx 2.722 ~\textrm{N}## in magnitude

    Is this the correct answer?
     
  2. jcsd
  3. Sep 17, 2014 #2

    ehild

    User Avatar
    Homework Helper
    Gold Member

    The solution is correct in principle, but you rounded off the acceleration too much, therefore the second digit of T is inaccurate. You could have cancelled a and get T directly.

    ehild
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Tension between two sliding blocks
Loading...