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Homework Help: Impulsive tension question

  1. Jul 30, 2012 #1
    1. The problem statement, all variables and given/known data
    A particle A, of mass 3kg, is connected by light, inextensible strings to particles B and C, of masses 5kg and 1kg respectively. They lie at rest on a smooth horizontal plane, with the strings just taut and angle BAC=theta. A then receives and impulse directed away from B and C along the bisector of the angle BAC.Show that A starts to move at an angle alpha to the direction of the impulse, where

    tan (alpha) = 2 sin (theta)/6-3cos(theta)

    Please provide detailed explanations along with your answer, thanks in advance! :D

    2. Relevant equations

    3. The attempt at a solution
    Sorry I don't even know where to start! Please help me with this question, thanks in advance! :)
  2. jcsd
  3. Jul 30, 2012 #2


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    Oh goodie, another stringy problem :tongue2:. Ok, some things to consider:

    1. What is the direction of the velocity of B after the impulse? of C?
    2. There is an important constraint condition relating the velocity of A and the velocity of B after the impulse. What is it? Can you express it mathematically? Similarly for A and C.
    3. What can you say about the total linear momentum of the system after the impulse? In particular, what is the value of the component of the total momentum in a direction that’s perpendicular to the impulse?
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