Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Need help on Practice Problems PLEASE

  1. Mar 17, 2010 #1
    Need help on Practice Problems PLEASE!!

    Trying to work practice problems before I do the homework & I need help. If someone could show me step-by-step bow to do these two problems that would be GREAT.

    A weight of 12 N is located at a distance of 14 cm from the fulcrum of a simple balance beam. At what distance from the fulcrum should a weight of 21 N be placed on the opposite side in order to balance the system?

    A weight of 5 N is located 13 cm from the fulcrum on the beam of a simple balance. What weight should be placed at a point 7 cm from the fulcrum on the opposite side in order to balance the system?
     
  2. jcsd
  3. Mar 17, 2010 #2
    Re: Need help on Practice Problems PLEASE!!

    Welcome to PF.

    I won't do them for you, but I will tell you the essence of each problem.

    The first problem is torque. I assume you've got access to the equation for torque. You have a certain force, a certain distance away from a "pivotal point". And you want to figure out the distance of the other force, so that the toqrues are equal.

    aaaand it looks llke the second problem is the same. You want me to tell you how to do the step by step answer so that you can memorize is and re apply it, but what happens when the problem integrates other concepts? Plus, these problems are very basic, and if you cannot do them already, or have no idea how to do them, do a bit of reading and it shouldn't be an issue.

    Cheers
     
  4. Mar 17, 2010 #3
    Re: Need help on Practice Problems PLEASE!!

    thank you!! i understand it now. my professor didn't explain it well.
     
  5. Mar 17, 2010 #4
    Re: Need help on Practice Problems PLEASE!!

    right on.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook