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!

One mass on, one half off, attached by a string

  1. Dec 2, 2007 #1
    1. The problem statement, all variables and given/known data
    Two equal masses (A and B) are attaced by a massless string of length L. Mass A is on a cliff and B is being held even with the cliff but a length L/2 away from the edge. If you drop mass B from this position, would mass B swing down and hit the edge of the cliff before mass A reaches the edge of the cliff?

    2. Relevant equations
    No equations are necessary according to the problem

    3. The attempt at a solution
    I'm just supposed to explain my reasoning for my answer. So my answer goes...

    Mass A would reach the edge of the cliff because as mass B falls and pulls on A, the radius of the arc that B would need to make to reach the edge of the cliff would continually increase, thus not allowing B to hit the edge of the cliff.

    Does this make sense or am I just making stuff up? Is there a better "logical" explaination that would seem to fit better with physics?
  2. jcsd
  3. Dec 2, 2007 #2
    Addition... as for the actual question, mass A is L/2 away from the edge of the cliff. So the string is taut (the string won't stretch as mass B falls either).
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook