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Basic Physics, help!

  • 31-12-2011 8:27pm
    #1
    DEVEREUX
    Registered Users, Registered Users 2 Posts: 541 ✭✭✭


    If two men pull on an elastic cable in opposite directions with equal force of 500N. Cable diameter is 4cm. What is the stress on cable?

    I'm confused as to what the force acting on the cable is, I know you get the stress with force divided by the area.

    Help getting past this before 2011 ends appreciated:)


Comments

  • #2
    Morbert
    Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    DEVEREUX wrote: »
    If two men pull on an elastic cable in opposite directions with equal force of 500N. Cable diameter is 4cm. What is the stress on cable?

    I'm confused as to what the force acting on the cable is, I know you get the stress with force divided by the area.

    Help getting past this before 2011 ends appreciated:)

    Strictly speaking, the net force acting on the cable is 0 N. But what you are looking for is the stress-inducing force. In this case, it is 500N, as the scenario is equivalent to one man pulling on an elastic cable with a force of 500N, with the other end of the cable fixed to an immovable wall.

    In general, if F_1 is the force applied by one man, and F_2 is the force applied by the other, in the opposite direction, then the stress-inducing force is the smaller of the two.


  • #3
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 93,583 Mod ✭✭✭✭Capt'n Midnight


    If you check what units stress is measured in it should give you a clue.


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