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Impulse Force on support?

  1. Jul 2, 2015 #1
    Hi, i have a question..

    I need to make a "bumper project" as shown in figure.
    I have all the geometric information about system and also know weight and energy which is transferred.
    I need to calculate the support reaction but i can not convert the energy to the force without "impact time". (F * t = m * V )

    Also, i m not sure is there any reaction force on the supports because it s a pin connection.
    Is it possible to calculate F???
  2. jcsd
  3. Jul 2, 2015 #2


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    So is the pendulum dropping down and hitting the block or is the block sliding into the pendulum? Before the collision, the pendulum has a well defined angular velocity. I believe you would be able to set up a differential equation using friction and gravity (on the pendulum) and appropriate initial conditions. Would you mind clarifying what you're looking for?
  4. Jul 2, 2015 #3
    Thank you BiGyElLoWhat.

    Pendulum is dropping down and hitting the block and yes, angular velocity is known (calculated).

    Actually, the main question is that "is there any force transferred to support?" If yes, second step, which is the hardest part, is to calculate amount of force.
  5. Jul 2, 2015 #4


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    I think the short answer would be yes.

    There is an impulse on the pendulum by the block, and in turn the rod by the pendulum, and as they contact, the ball 'tries' to act as a pivot point about which the rod will rotate. Is the support loose or fixed?

    Another thing to consider: If you're neglecting the rod's moment of inertia, (and thus it's kinetic energy), you could probably neglect the force on the support as well, as I would think it should be negligible in comparison. Some one may want to correct me on this fact, though.
  6. Jul 2, 2015 #5


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  7. Jul 3, 2015 #6
    Thank you for answers..
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